Maximum Fit Magazine

I've been reading alot on RBMs and the learning algorithm developed by Hinton, but I can't figure out exactly how to implement the algorithm for updating the weights. I know ÄW.ij = ?(<V.i H.j(data) - <V.i H.j(model)), but I can't quite grasp what <V.i H.j(data) and (model) are. I've read that they're the frequency that V.i and H.j are both 1 or 0. Whats (data) and whats (model)? I think I'm confusing myself, but I can't figure it out. Also, when am I supposed to apply the weight changes throughout the algorithm? Should I change the biases at the same time? I need help, Thanks