First, ask yourself the following questions:
– Are you prepared to pack up and move to North Dakota, Oklahoma, Utah, Bulgaria, or any other location where you may be offered a tenure-track job? More to the point, are you and your loved ones prepared to spend an average of three years not knowing where you might be offered a job, but ready to pack up and move there anyway?
– In any given year, there are more than twice as many new Ph.D’s in English than there are tenure-track jobs advertised. If you are among the people who never do find permanent employment, will you still feel that grad school was worth it for its own sake? Put another way, does seven to ten years of geeking out on your subject on a grad student’s stipend sound like great fun even if it never leads to a job, or are you going to feel like you wasted all that time if you take the gamble and lose?
– Can you face the thought of teaching lots and lots and lots of freshman composition, every semester for the rest of your life?
If the answer to all of those questions is yes, the best people to talk to are your undergraduate professors (especially younger ones who have a good handle on what the job market is like these days). You’ll need rec letters from them anyway, and they can give you better advice than a career counselor can.
Take the GRE. Apply to grad programs. It’s best to apply widely and aim high, as the selection criteria for different programs can be somewhat capricious. Expect to pay several hundred dollars in application fees alone. Write a kick-ass statement of purpose, highlighting your prior teaching experience as well as your research interests, and a kick-ass writing sample.
Do not go to a grad program that does not offer you funding. If they want you, they will offer you a fellowship or assistantship, and going into debt to get a Ph.D. in the humanities is a bad idea. If you are lucky enough to be offered funding at two or more programs, visit the campuses before making a decision. Try to get a feel for the climate: do grad students seem happy? Do they appear to like each other, or are they locked in a Darwinian state of competition? Do the professors seem genuinely interested in mentoring grad students, or do they lock themselves inside their offices and only rarely condescend to mingle with the populace? You’ll be spending a minimum of six years of your life with these people, and possibly closer to ten, so choose carefully. Also, find out all you can about the funding structure of the program, the amount and kind of teaching grad students usually do, and the placement rate for graduates.
Grad school is like an apprenticeship. The first few years, while you’re still taking courses, may feel a lot like undergrad, but the coursework is not the most important thing. Think of each term paper as a starting point, not an ending point: rework, revise, present at conferences. Seek out faculty who can tell you how to do these things. Make friends with the other students in your program. You’re all in this together, and the people who can give you the real dope about how things work are usually the students who are a few years farther along than you are.
Beware of advice from professors who believe the only kind of job worth having is a job at a big research university. Realistically, only a tiny minority of grad students are going to end up in these jobs. Get the kind of teaching experience that will make you look attractive to a regional state school, a small liberal arts college, or a community college. (The fact that you’ve taught at the high school level will be a big plus for some of these institutions; nearly all will want to know that you can teach freshman comp and an intro-level literature survey. Many of them will not care a great deal about your research, as long as you’re doing something. This is an utterly foreign world to profs at research institutions, and they often give their grads well-meaning advice that is completely wrong for other types of schools.)
Do what it takes to finish your dissertation. It doesn’t have to be perfect; you can always revise later. It does need to be signed, sealed, and approved before most hiring committees will take a chance on you.
Good luck! It’s a cool job; that’s why everyone wants to do it.