Fiber is great, try to get it from real foods before you resort to supplements. Soluble fiber is great, it has been shown to help reduce serum cholesterol. It is found in things like brown rice, oat bran, oatmeal, etc.... Insoluble fiber is equally as good, it adds bulk to the stool, hence helps reduce the risk of colon cancer. It is found in your fruits and veggies mainly. Good luck!
Ryan