Painting 101 ?'s

Okay, I've read some here. Can't find one thread that was long and really good, talked about not doing the w that you see on all the shows, nice even strokes and a bunch of other stuff.

Probably stupid questions, but here goes. I've been priming some rooms, treating them as practice sessions (couple had issues and felt it was worth it). I'm trying not to apply pressure with the roller on a pole, but I still am getting a little squeeze out sometimes. Any suggestions? Also, how much paint should be on the roller to start with? I've been practicing doing the cutting out and feel good about that. Feel pretty good with roller right now, but figured I'd ask since I've been putting a lot of work on the house and rooms and didn't want to mess them up now. I'll be using BM Regal, at least I think that is the name.