Baseball Prospectus 2011. Good in-depth analysis of teams and players, including previous stats, projected stats, chances of breakout/improvement/collapse, and comparisons to other players. Includes a smaller section on minor league players. This book was invaluable to me when I was first starting out as a fantasy baseball manager--I'm pretty sure I cross-referenced every player I thought about drafting in this book. A new edition is published every year, released around February, just in time for spring training. Pick one up (and do it at Amazon, so much cheaper than B&N or other bookstores).
Also a resource I use a lot: Fantasy Baseball Cafe. It has articles, mock drafts, podcasts, rankings, and, most useful, user forums. You'll have to create an account and log in in order to be able to post to the forums. One thread that is very popular (and thus peppered with more useless posts than most others) is the closers thread that keeps managers up to date with who's closing where, including a very helpful first page that keeps track of who the primary closer is, what their grip on the job is, and who's lurking to take over. There's also a Cafe for fantasy football, basketball, and hockey.