Very well respected summer ball league with many top-notch players from across the US. They draw big crowds in many areas.
Go to the "after high school section" here and do a search. You'll find more 1st hand info there.
As Cabbagedad said Coach Miller for m Cuesta College is a long time JC coach that is very respected in CA.
My son played in the WCL last summer so send me a pm if you want more input.
Good luck!