As for learning, polyglot mentioned Light, Science and Magic which is one of the best lighting books, ever. Marc Hauser's Bold and Simple
taught me a lot about lighting for portraits.
The main thing is to get a reliable setup -- two lights is a great place to start -- and just get to work. Make tons of portraits and you'll learn quickly, especially if you're willing to just shoot digital for a while. The instant feedback really works wonders. Any time I shoot MF or LF portraits, digital is my Polaroid.