Your largest maintenance item is the motor so grab the shop manual for your particular engine. You need year, manufacturer, and typically HP rating.
As for the boat itself...you probably won't find a parts manual for it as Sylvan used parts that were off the shelf from other manufacturers. For instance, you windshield, if equipped, probably has a stamping in the glass saying Taylor Made (or similar). So if you want to replace certain parts - cleats, drain plugs, cup holders, seats, etc...look no further than iboats as you do get a forum discount.
