I absolutely agree that if you have had no formal art training, do an Anatomy for the artist course, and if you are going to be doing 3D texturing and lighting (not just modeling), then do a painting course, it will give you a really good understanding of light and texture which is indispensible.
You don't have to do an expensive course, even one of those cheap evening 'adult ed' courses would be just fine. The first thing we would do with any modeller was to put them through some short traditional art courses, it makes a *huge* difference.