The biggest challenge for me is that these are all paper books on my actual bookshelves -- I have been reading only e-books since you, yourself, made a convert out of me in May 2009. The books I grabbed for this challenge had a thick layer of dust on them and cracking them open is going to be... interesting.
So what are you going to start with? I am going to go for The Richest Man in Babylon. One, because it is the shortest and two, because I suspect it may also be the most useful.
Interesting side note: I've owned this book for over 20 years. Wow. That's a lot of traveling for a slim book to never be read. It was recommended to me in high school by one of my favorite teachers, a guy you also know: Michael Pollack. He swore by its sound financial advice.
Probably should have read it back then when I was young and still impressionable, but hey! It's never too late to learn, right?
So what's your first book?