The MLA Job Information List goes live in about a week, and ABDs, new Ph.D.s, adjuncts, instructors, and tenure-track people looking to "trade up" will all take a look. (So will those of us on search committees, since we'll hope that our carefully crafted, word-by-argued-about-word ad will bring in good applicants.)
Some other things will happen, too. The forums at the Chronicle of Higher Education will overflow with questions ("What does this school REALLY mean if it asks for underwater saltwater basketweaving instead of just underwater basketweaving?") and furious screeds about slights in the hiring process, some of which verge from rude to heinous and others of which can't be helped ("It's been two weeks and I haven't heard yet. What is WRONG with these people?").
One of the good things that will happen is that the Chronicle, and Inside Higher Ed, and the forums will all offer some good advice. Mentors will offer good advice. Departments will offer good advice.
Bloggers will offer good advice, too: Tenured Radical, for example, has promised a series on the search process. If you've read all these job-related blog posts for the past several years, the ones posted by Bardiac, Tenured Radical, Dr. Crazy, Sisyphus, Dean Dad, Narratives, and CitizenSE, among others (you can see a list here, in a post I wrote last year about the job search), you'll see that we're all saying variations on the same things. Every year we're all saying variations on the same things.
And that's a good thing. What this consistency says is that there are conventions, but there is no magic bullet, no secret formula that will guarantee a job. It's not news that there are a lot more people looking for jobs in MLA fields than there are jobs. Ultimately, and I know everyone has heard this before, it's not about the job seeker; it's about what the department needs, or thinks it needs. The only thing you can really do is to present yourself in a way that makes the department believe that you can answer those needs, and this is the art of the job letter.