[enters thread sheepishly]
:o golly.
Well, I dunno, I don’t really think about it that much, you know? I’m a pretty verbal person, and a fast typist, so I don’t spend much time sitting there and racking my brain for search terms or strings, I just start typing in words. A good starting point is just the main words. If I want to know something about what Sitchin says about Sumerian astronomy, I’d put in something like “sitchin sumerian astronomy”. Abuse Angel wanted to know how to fold a heart into a note, so I put in “origami heart”. Holden Caulfield wanted to know a definition of “organic” as applied to food standards, so first I put in “FDA definition standard”, and then that brought up a website that mentioned the new USDA standard, so I put in something like “USDA national standard organic”.
It also takes a certain amount of reading the hits that turn up, to make sure they aren’t totally lame. It doesn’t automatically hold true that Hit #1 will be the best hit for your purposes.
The way Google works, as I understand it, is that it searches, not every page on the Web, but only the pages that somebody, somewhere, has linked on his Web page. This means that your Hit #1 is going to be the most popular reference to be cited on people’s Web pages, all over the Internet, but not necessarily the most correct, or the most useful.
Advanced Search and Search Within Results are also very useful. It’s also important to remember that Google searches for exactly the spelling you tell it to, so for some things you have to try different spellings, and try word substitutions, like:
Cape Malay women remove teeth fellatio
Cape Malay women knock out teeth fellatio
Cape Malay women knock out teeth oral sex
Cape Malay women remove teeth oral sex
Cape Malays remove teeth fellatio
Cape Malays knock out teeth fellatio
Cape Malays knock out teeth oral sex
Cape Malays remove teeth oral sex
See? Sooner or later something useful comes up, and as in the “Prostitutes remove teeth to facilitate oral sex” thread, if nothing comes up, well, that tells you something, too.
It helps if you’re a verbal, fast typist. 
I would not even waste my time Asking Jeeves, sorry. Jeeves only works if you’re looking for something really mainstream, like breast cancer support groups, or Miss Cleo. But with other, General Questions-type stuff, all Jeeves can do is guess, and he’s usually wrong.
I also have a lot of extremely useful websites bookmarked, like Merriam-Webster and HowStuffWorks.com, not to mention a lot of FDA and USPS and USDA websites. This speeds things up considerably.
Anyway, overall it’s just a “practice makes perfect” thing. Keep doing it and you’ll get the hang of it. It’s not rocket science. 