In my opinion Tony Ryder's book is the best drawing book I have ever read, by far.
Ryder, Anthony,
"The Artist's Complete Guide to Figure Drawing". Watson Guptill 2000
I'm taking a portrait painting class with him soon, so I figured his book would be required reading, if for no other reason than to be familiar with the terminology. I was delighted that his technique was so helpful to me.
As I read through it I tried a few drawings using his method and I found the technique so helpful that I plan on using it for every drawing I do. I found myself following his advice (about checking angles, and looking for forms upon forms) every day on the current portrait I'm painting too.
I highly recommend not just reading through the book, but trying out the techniques on a few practice drawings and see what you think.