If you are an NBA fan, the best $10 you can spend this year is on the PDF edition of Pro Basketball Prospectus 2010-2011, out today.
If you have an iPad, all the better -- it renders amazingly. But even if you are merely going to read it on your laptop (which is how I consumed it last year), it is an invaluable resource heading into the season, and something you can digest in small bites when you have the time.
My favorite part are the player comps. Who doesn't want to know that they are compared to the incomparable Caldwell Jones? (I'm looking at you, Hilton Armstrong.)