Here is a list of some good books. They can give you an idea of the resources available. Purchase is not necessary.
Check with the local library and see about checking out books and DVD's. So, if you are eager to learn even more between classes, here is a sample of the resources you might fin.
Hazel Harrison. How to Paint and Draw: A complete course on practical and creative techniques. Art School series. Features clear, easy to follow hints and directions for drawing, watercolor, oil & acrylic and pastel. Hermes House, London, 2003. ISBN: 0-681-30397-2
Foster Caddell. Keys to Successful Color: a guide for landscape painters in oil. Watson-Guptill, New York, 1979. ISBN: 0-823-2580-2
Landscapes: a step-by-step guide. Barnes and Noble, New York, 2003. ISBN: 0-7607-4270-7