When checking out the yoga class schedule at your local gym or studio, your brain can get all twisted up trying to figure out which class to take, and you haven't even stepped on a mat yet. Allow me to explain.
Vinyasa or Flow - Usually a fast paced class, the instructor plays music and makes up the sequence, like a choreographed dance.
Beginner - This is a perfect class for someone who's just starting out. It's usually an hour or less and paced much slower.
Power - This is fast-paced, difficult, and based on Ashtanga Yoga.
Mixed - This could either mean "mixed levels," for both beginners and experts, or it could mean a mix of different postures taken from different styles of Yoga. I'd call and ask just to make sure.
Hatha - Literally means "sun moon" and is usually slower and more gentle.