Friend of the site Glenn Fleishman is the reigning Jeopardy champion, and he has written a detailed account for Boing Boing.
His preparation was intense:
I knew my general knowledge was rusty, and consulted piles of almanacs, watched the show, and went through the J-Archive, a compendium of every clue and question ever posed on Jeopardy, run by fans and unaffiliated with the show. I read the three best-known Jeopardy books, too: Secrets of the Jeopardy Champions (1992), Prisoner of Trebekistan (2006), and the aforementioned Brainiac (also 2006). I had coffee with Jennings, who lives in the Seattle area, just before appearing, which was a nice morale boost. (I have an article about the studying process over at The Economist's Babbage blog.)
What I didn't know is that there is now an online test to become a contestant. It's currently only open for kids.
Kottke linked to a video of Glenn's impressive first-night comeback win.
Congrats Glenn! Well played. As a side note, am I the only one who misses Trebek's mustache?