check out the vapor spot, it's on van nuys blvd just south of the 101 in sherman oaks. it gets pretty busy, but they'll set you up with everything you need, show you exactly how to use all of your equipment, and let you taste as many different flavors as you want.
This is actually one of the 2 spots in Sherman Oaks that I'm planning on checking out today. I've heard good things about them, so I'm hopeful