On the building of the figure -- the wire frame works fine for some. I prefer the "balloon" method. There is no right way -- but there sure are a whole passle of wrong ways! Find what works for you -- even if it means making up your own! (The idea of the boxes sounds good, as long as you don't become dependent on it. The object of the exercise, after all, is to get rid of the training wheels!)

How to Draw Comics the Marvel Way was my introduction to a lot of the art techniques I still use today.  What an eye-opening experience studying this book was (found out you use a brush for inking, f'rinstance).

John Buscema's art lessons were simple, yet amazing.  Over the years, I found myself developing a combination of the stick figure, balloon, and scribble methods that John showed in the book (like JB said above, find what works for you!).  It's still one of the books I pull off the shelf the most when I have a question about art.