I know of four bipolar 1 with or without psychotic features, bipolar 2, bipolar nos, and cyclothimia. With bipolar 1 you get full blown mania and major depression, with bipolar 2 you get hypomania and major depression. cyclothimia fluctuates between minor depression and hypomania. Bipolar nos is where they put you when you obviously show some symptoms of bipolar disorder but they do not know which classification to put you in. There is also schizoaffective disorder which can have some symptoms simmilar to bipolar disorder. I think it is actually on the schizophrenia spectrum but from my understanding it can be like a cross between bipolar and schizophrenia. I hope this helps maybe you could do a google search for bipolar spectrum, or just bipolar to get some more in depth information.
http://www.psycom.net/depression.central.lieber.html