Turid Rugaas is well known for her expertise in dog communication and canine language. I highly recommend all of her material. But truth be told, you probably don't need to spend the $10 it'll cost you to get this booklet. The booklet is very small, filled with a lot of great pictures and a few paragraphs of instruction. If you don't need the glossy pictures and explanations then you can get all the same information for free on her website TuridRugaas.com. Just go to her Q&A section and look for all the articles on pulling.
If you do decide to buy this booklet, you'll find that the instructions she give are clear, concise and easy to follow. And most importantly of all, the method works. The best part is that there are no gimmicks, no special equipment to use, and no harsh corrections. There's also not really anything special to her method--which is basically the "stop and switch directions" method of loose leash walking, with lots of praise and some noise motivation added in to speed up the process. Understand that her goal is not to get your dog to heel on your side all the time, but just to walk on a loose leash. As long as the dog isn't pulling, she doesn't care if it's in front of you or behind you or walking in circles next to you.
I will say that she does seem to go a bit overboard (perhaps even exaggerating the negatives) in the sections where she explains why other methods and equipment don't work. Her hatred for halters, chokers, pinch collars, short leashes, no-pull harnesses, and corrections of any kind comes through exceedingly loud and clear. She encourages the reader to use just a simple buckle collar and lots of a positive praise and reinforcement. That works for me.