The Grove, Anaheim
The Grove was once a dinner theater now turned small concert venue. It's a great place to see up and comers! The setting is very intimate, and they have some pretty decent names how up here, both in the comedy and music areas. The ticket prices aren't bad either. You can buy tickets plenty in advance and if you are in town for more than a few days, it is a good option for some nighttime entertainment.
Give the website a look over and see if anyone is coming up that you like. You can buy the tickets in advance online. Enjoy!