Generally speaking, anywhere from one to two weeks, depending on the book. Though I never accept a deadline without looking at a sample of the book first. If it’s 500 pages of Microsoft Office stuff, which I’m familiar with and is already well-structured, I can do it in a few days. If it’s 500 pages on Cartesian philosophy, I wouldn’t agree to anything less than a month.
How well do you have to know the subject in order to index a book on it? It seems to me that you would have to have some familiarity with the subject in order to be sure you were catching all the references.
For example, suppose you were indexing a book on baseball. And there was a anecdote with somebody saying something like “Yeah, I remember the time me and the Yankee Clipper visiting Boston. Most people don’t know this but he loved lobster. We must have eaten fifty of them that weekend.”
Now a person familiar with baseball would know to index this under “DiMaggio, Joe - love of lobsters” but somebody unfamiliar with baseball might have an index entry for DiMaggio that missed this mention of him.
Knowledge of subject material helps, yeah. Although in this case it seems unlikely that it wouldn’t be clear from context that “Yankee Clipper” referred to Joe DiMaggio, so you’d be able to pick it up that way. And if you weren’t able to tell who the nickname referred to from context, you’d Google it to find out.
But indexers do tend to specialize in certain subject areas. Like, I will not take a math book or science books that are above a certain audience level. There are indexers that specialize in high-level chemistry books, in medical texts, etc.
Yes, that would be best. In my experience it often does not happen, however. (I am sure these are not books that you have indexed, of course. :))
No question, but I wanted to tell you how much I appreciate your work. Someone once said, “A nonfiction book without an index is useless”, and I’ve often found it to be true. Sadly, they seem to be quite common. Memoirs, for example, often don’t come with indexes.
Actually, I would appreciate an index even for fiction sometimes. Once in a while there’s a character that I don’t remember and it would be nice to look up where he was first introduced.
You mean you didn’t even know that Cat’s Cradle is a must read for someone in your profession? This was the very first thing I thought of seeing the thread title.
I am surprised you hang out with “book people” and they don’t bring this up constantly.
It’s like being a bobby named “Jack Ripper” and no one brings up the unpleasantness in Whitechapel years ago.
I once worked with a guy named Robert Heinlein. Naturally I asked him if he was related to the author. And he said “What author?”
Now he may have been pulling my leg. But he seemed sincere (and I was his boss’s boss which normally reduced the amount of leg pulling new employees were willing to try). So I assume that somehow he had managed to reach adulthood without ever having heard that there was a relatively famous author with the same unusual name as his.
Going from the opposite direction, how much do you find you retain from the books you index? If you were indexing a book on a subject you weren’t familiar with beforehand, would you absorb the contents of the book from reading it to index it or do you just sort of skim through the book looking for index points without seeing its overall subject?
What’s the most obscure subject you’ve indexed?
-D/a
Do you work freelance, or are you employed by some publishing company? If freelance, how do you usually obtain work?
Also, when you get an assignment or contract, does the publisher provide you the text in some computer-readable format, like a Word document or even just a .txt file?
I do, actually. I should probably update since it sounds like they’ve at least improved the index. 
I retain a fair bit, actually, especially from books that I find to be particularly interesting. I have a much better understanding of international privacy law, for example, after doing a recent series of three books on the topic. And yes, I do have to read the entire book. I usually start by scanning the table of contents and the major headings (assuming the book is laid out with headings and subheadings) to get a sense of what major areas are covered, but after that I just dive in with chapter 1 and start reading/indexing the thing.
I’m going to have to go with the oil crop biorefineries book I mentioned above. I also indexed the rules manual for the Fury of Dracula board game, but that was just a hobby project I did, and not officially for pay. (You can find it on boardgamegeek.com in the Fury of Dracula files section, if you’re interested. 
)
I am entirely freelance these days, and that is how the vast majority of indexers work. I am in the relatively unusual position of having actually been an in-house indexer with regular employee status for a while at my previous job, but yes, these days I do 100% freelance work. I tend to get jobs either through existing contacts that I have at publishing companies – when I started freelancing, I let all of my friends know, and it turns out that a few of them work in the world of publishing and were able to send some work my way, and those jobs have turned into more jobs, etc. – or via publishers/authors searching the Indexer Locator on the ASI website. I did have one person who found me directly via my own business website. You have to pay to be a member of ASI, and you have to pay an additional fee to be listed in the Indexer Locator, but the two jobs I got that way just this year paid for the fee about 10 times over, so it’s definitely been worth it.
As for file format, most often I get PDFs of page proofs. For a standard index, the proofs come to me after page layout, because otherwise how would I know what the page numbers were? However, I will sometimes get an embedded index request, and in that case they send me the original chapter files in whatever layout program they’re using. Most frequently this is InDesign, although I’ve done a fair few Word embedded indexes also.
Edit: When I first started freelancing a few years ago, it was not uncommon to hear about publishers still FedExing actual page proofs out to indexers. That used to be the standard procedure. But by the time I really got my freelancing biz up and running, nobody was still using physical proofs anymore. It’s all PDFs these days.
I was talking to some of the old-timers at the last workshop I went to, and they remember actually compiling indexes using index cards, before the days of desktop publishing and email. I…have no words.
How much do you get paid per (whatever you get paid per)?
Rates are per-page. I charge between $3-$5 per page, depending on the material. The denser the information, the higher the rate, basically. I also charge on the lower end of the scale for books that have a lot of white space and graphics on the page.
I actually need to update my website. When I first started out, I quoted $2.50/page as my low end, but I’ve been getting enough work in lately that I can afford to turn down lowball offers like that. Huzzah.
Do you typically deal with the author, an editor, or both?
How do the authors you’ve dealt with feel about you indexing their books? I’ve always insisted on doing my own indexing, just because I typically write on obscure subjects, and nobody else will know all of the interconnections, synonyms, and so forth. I’ve lectured on the subjects enough to know how people phrase their questions and what words they’re likely to look for. Also, if I pay attention and tag words as I go, half the indexing work is done by the time I finish writing.
Do you ever have a little fun in your indexes? For example, in a computer manual I wrote years ago, I had “Loop, infinite: See infinite loop” and “Infinite loop: see loop, infinite” (the text of the book never mentioned infinite loops).
No, I generally keep things straightforward. That’s a good one, though. 
I usually work with production editors, although I’ve had a couple of jobs that came directly from the author. In every case where I’ve had the opportunity to get feedback from the author, they’ve been very pleased with my work.
I hope you don’t mind, but since your user name = your real name, I took the liberty of looking up one of your works on Amazon that has the index available for view. (The Closed Captioning Handbook.) The index is decent and certainly usable, and a lot better than some of the author-created indexes I’ve seen. But it could still use some work. 
I could go into more detail if you care. (I don’t mean to be all harshing out on your self-indexing, because seriously, it is really so much better than a lot of the ones I’ve seen that were clearly done either by the author or by someone whose entire professional training consists of reading the Help documentation for the MS Word indexing feature, if you know what I mean. But I can still look at it and see that it wasn’t done by a pro.)
Any advice for someone who’s seriously thinking about starting this as a career? It sounds right up my alley–I’m a SAHM, and I’m hoping to be able to work from home when the kids start school full time in about three years, so I have time to train in the meantime. Assuming I’m any good at it once I’ve taken the course (I need to take the course, right?), is there enough work to be had out there?
Three years is probably a good timeframe for working up from zero to “regular work.” There are a few courses out there that you can take. One is offered, bizarrely, through the USDA, and was the gold standard for a long time. There is also now a course offered through the UC Berkeley Extension program. That’s the one I took (after a few years of on-the-job training). Different people prefer different programs, but I thought the Berkeley one was pretty good. YMMV.
Marketing yourself and getting clients will probably be the tough part. There’s a lot of advice out there on how to do that, and a lot of it is outdated and some of it is bad. All I can tell you is to work any publishing contacts you happen to have, no matter how tenuous, put up a website, and sign up for the ASI Indexer Locator. And do good work, so that people call you back a second time.
Expect rush deadlines and late nights if you get serious about this. I don’t always have a lot of control over when jobs come in, and sometimes several land on me all at once. It helps if you’re a fast reader. (It also helps if you’re a fast typist, actually.) If you decide to go for it and have any questions, feel free to message me.
Not a problem. If I minded, I wouldn’t have used my real name here. I hadn’t even realized they made that index viewable on Amazon.
Now you have me all curious. What are the giveaways that an index wasn’t done by a professional indexer? What would you have done differently? I’m not talking about the style or presentation of the index (the publisher determined that), but the actual content.
OK, well, this isn’t a thorough critique, but as I was paging through, here are some things I saw:
First of all, you have a ton of orphaned subheadings. This is more of a formatting thing than an information organization thing, but it’s still a bit messy. When your main entry only has one subheading, it’s better to combine it into the main head. It saves space and removes redundancy. For example:
Caption Colorado
–cybercasting, 14
You could make that Caption Colorado cybercasting, 14. Or better yet, Caption Colorado, 14, since that’s the only entry you have on Caption Colorado, so if the reader is interested in Caption Colorado, they’ll know to go to that single page.
Also, you send the reader chasing all over the index with some of your cross-references. For example, you have “yen. See currency, yen.” Fair enough, but then you go to the currency entry and find:
currency
–yen, 313
So you forced the reader to flip through several pages of index just to get a single page number. What would work better is to have: “yen, 313. See also currency” if you think it’s important to let the reader know that there are other currency entries available.
In a couple of places you have entries that are redundant and probably should have been combined. For example:
Emergency Alert System, 42
emergency alerts, 89
Emergency Broadcast System, 42
emergency broadcasting, 42
emergency broadcasts, 105
Those should probably be combined into a single entry. Maybe two entries, if you feel it’s important to distinguish between the official Alert/Broadcast System and the lowercase general emergency broadcasts. But the way it is now is confusing to the reader: are all of these things different? Is there a significant difference between emergency broadcasting and emergency broadcasts? Also, three of these have the same page number anyway, which indicates to me that these are closely-related topics, if not the exact same topic.
Similarly, you have:
Subtitled Videos Project, 12
subtitles, 218
subtitling
–defined, 4
First off, there’s another orphaned subheading. But ignoring that, I don’t think that the difference between subtitles and subtitling is significant enough to warrant two separate entries. Additionally, it seems to me that the Subtitled Videos Project probably has something to do with subtitles or subtitling, and yet page 12 is not covered under either “subtitles” or “subtitling”.
You have entries (not next to each other, but separated throughout the index; I’m just aggregated them here to illustrate my point):
Arabic-language captioning, 316
Danish-language captioning
–character set, 314
Finnish-language captioning
–character set, 314
There are other entries throughout the index for captioning in other languages. Some of them have a single subentry for “character set” and some don’t, which is an inconsistency I’d probably fix. (Additionally, those are orphaned subheadings anyway.) But, you also have an entry in the index for “character sets”. The only place in this entry that pages 314 and 316 are covered is in a subentry, “line 21 extended.” You don’t have a subentry for “foreign languages” or anything that would cover the topic of foreign-language character sets, which is important enough to warrant several other entries throughout the index. You also don’t have a main heading anywhere in the index for “languages” or “foreign languages”, etc. It looks like most of the foreign language stuff is grouped in a fairly tight page range, so that would have been a matter of simply including “foreign languages, 314-316” or something like that, to pick up readers who want to know where the main discussion on that is.
You have an entry “caption volume control, 52.” Well, the whole book is about captioning. You don’t want to have every single entry as a subentry of “captioning” or that would be the entire index, if you follow my meaning. So while it’s not exactly wrong to have an entry for “caption volume control,” you’re going to pick up more readers if you double-post that at “volume control, 52.” Or if you feel that won’t be clear enough, “volume control for captions, 52.” But you should definitely have something in the Vs for “volume.”
There are a couple of “see references” that have page numbers after them, which I think is probably due to having accidentally put the “see” reference in the subentry field of the indexing dialog box, instead of the cross-reference field. E.g.:
typefaces
–see fonts, 38
OK, that’s probably enough. I could talk about indexes all day but those are what immediately leapt out at me.