The covers link to The Tattered Cover (to promote indie bookstores a bit) in case you'd like more info. Here's number thirteen:
Carter's Big Break, by Brent Crawford
What did I love about this? Well, it's hysterically funny in places. And when I wasn't laughing out loud, I still appreciated the wry -- and definitely slightly older -- humor in each situation. This is a sequel, and I felt that Carter has definitely matured, but his outlook is still very humorous (not quite as teen-boy crude/funny as the first book). And he's a good guy, so it's fun to be in his shoes for a while.
The story: Carter still doesn't quite get girls, and when he mis-reacts to his girlfriend, they break up. It doesn't help that Carter gets a role in the movie his girlfriend wanted to be a part of -- and he's opposite an actual teen (female) movie star! Soon everyone thinks Carter's gotten together with the movie star, but he still wants his ex...and he's rather shocked at the movie star's so-called life. Being Carter, he finds a way to work everything out by the end...mostly.
I recommend both this and the first book to anyone with pre-teen/teen boys -- and everyone else too :) Truly a couple of the funniest books (with enough compassion to make them linger) that I've ever read!