In the picture for this post you can see a grab of David Kassan's DVD sales page. The reason it is there, is if you really want to be the best, you should know how to draw. I suggest buying this DVD and anything from David Kassan, Jeremy Lipking or Tony Pro. If you want to learn, why not learn form the best?
The saying is true, if you can draw it will help you sculpt better. I drew hundreds of portrait commissions before I ever picked up clay. However, as indicated in this article, just because you can draw, doesn't mean you will be able to sculpt. Having said that, In Graduate school, as a sculpting major, we were required to take drawing classes. I will always be glad I took them.
Please do not think that I am suggesting art school. If anything, I council against it. Why spend 3 years and $100,000 on a degree which you will not be able to get a job with when you are finished?
I think going to the source of the best knowledge available is the key to succeeding in art. Which is why I tool a class from Master Sculptor Richard MacDonald a few years ago, and Human Anatomy for Sculptors with David Klass. The class was over $3,000. However, I learned more in a week that 3 years of Graduate school focusing on sculpture.
Synopsis: Learn to draw, learn from the best, stay away form art school. Especially the abstract sculpting department at The San Francisco Academy Of Art University. Think black plague of productivity. If you have to do art school, contact Erik Blome who teaches at The San Francisco AOA University, or Melinda Whitmore if you are on the East Coast.