Couple of on-line courses here:
http://www.boatsafe.com/
USCG navigation rules here:
http://www.navcen.uscg.gov/mwv/navrules/rotr_online.htm
Those sites are great and they will get you a discount on your insurance but they do not replace taking a comprehensive boating course with the USCG or Power Squadron. I still think of myself as a newbie and really learned a lot in those classes.
Just my .02..........
Enjoy and be safe!