This site gives an overview of what therapy is, the different types of therapy there are, when you should start therapy, how to pick the right therapist, and even information about insurance and therapy.  A great site for basic research.

Gives a basic definition of each of the major schools of therapy.  Enough information so that you get the main ideas behind each and can research the ones you want to more in-depth.  Provides crisis numbers and helps you find a therapist as well.

A more personal site about what therapy is, three major branches of therapy, and how to choose a therapist.  Includes references the author used and outside links for more information.

This site offers an overview of the four major theoretical orientations and what practices their therapists use during their sessions.  While it does not cover all the theories, it covers the major four very well.

This easy to follow site defines therapy in a basic manner, gives examples of when therapy is useful, and then offers brief definitions of each major type.