Daniel Nexon has some interesting thoughts and advice on the whole job-seeking process, all of which would be well-taken by the novice job-seeker. I would particularly reiterate his point about not “build[ing] an imaginary life for yourself,” something that is admittedly hard to avoid when trying to tailor the cover letter to the particular institution you are applying to. Bear in mind, though, that cover letters—unlike notes on Christmas cards given to family members—are not going to be shared around among the recipients, so you don’t need to make them that original.

Dan Drezner, from whom I got the link, fairly cogently summarizes the state of the job market thusly:

The academic job market, as I’ve witnessed it, is a globally rational but locally capricious system. Some people will undoubtedly slip through the cracks—but on the whole, talent is recognized and rewarded.

Mind you, that equilibrium state takes a long while to arrive for many, and it’s one punctuated by frequent instances of blind panic as you attempt to get your various files in order.