Published 
Public: Anyone can view. Are you familiar with any of the S&M friendly things that go on around town? One method of getting into the scene is to go where others play. As for what to know... well... to an extent it varies on the individual. Generally speaking, especially for a sub, you would want to know a bit about who you are getting involved with. I'm not exactly an expert in the scene, but I think its good to talk to somone a bit before jumping in and getting involved. Make sure you know what your limits are and are able to talk about it to them. Have a safeword that you can use to stop things if you feel uncomfortable.
Anyway, I hope that helps.