How about a hints & tips section. Just quick 1 or 2 para helpful bit that most people go "Ooooh! I didnt know you could do that." For instance: How to straighten scans. Use the ruler tool and lay it down a straight surface of the scanned, wonky image. Use Image/Transform/Rotate/Arbitrary and the degree difference from the horizontal/vertical will be already there. Just hit "rotate" and your'e done.