I just went through a gelcoat restoration job on my N20.
First, clean it with FSR "goop". Its blue. It comes in a jar at West Marine.
http://www.westmarine.com/webapp/wc...1151&partNumber=108753&langId=-1Then after a thorough washing.... comes the rubbing compound. It goes by quicker with a random orbit buffer.
http://www.westmarine.com/webapp/wc...&subdeptNum=10384&classNum=10385Then hit it with the finesse-it glaze with the buffer.
http://www.westmarine.com/webapp/wc...&subdeptNum=10384&classNum=10385Then finally hit it up with a wax of your choosing. I prefer the McLube Hullkote wax.
(Note to Rick, I tried looking for these products in the marine store but it seems that all thats available there is the cleaning wax)