Here's my best summary:
Well there's a rising movie star from NY (Vince) who brings his 2 friends (Turtle & Eric) to LA with him. Eric takes the job as his manager while they also shack up with his half brother (Drama). Jeremy Piven (Ari) acts as his agent (the best *A$$ on TV). So basically its like the real life of a movie star in Hollywood- In the 1st season Vince just finishes a movie with Jessica Alba, which had mixed reviews. Then he makes an Indie film that was in the Aspen film festival that caught the attention of James Cameron.
Vince beat out Leo Dicaprio and other actors to be the lead man in a high budget superhero movie, "Aquaman," starring opposite- Mandy Moore. But there's all this drama b/c Vince and Mandy used to date. Now we're up to now in the season 2. Its cool cuz of all the cameos of other actors playing themselves (Luke Wilson, Ralph Macchio, Pauly Shore, DJ Quik, Ali Larter, Mark Walburg, Jessica Alba, Brooke Shields, etc.)
I guess this is supposed to be somewhat like the life of Mark Walburg- who is the Exec. Producer of the show... anyways- enjoy the finale!!