Actually, from my experiences, and from what I've heard, Mondays are actually one of the busiest days in the park(everyone thinks that the park will be empty that day), and Fridays are very slow. Saturdays are busy, but Sundays also seem to not be that bad. I don't like to go to the popular rides first, especially Raptor and Millennium Force, because that's where EVERYONE seems to go in the morning. Magnum seems to be a good place to start, then just work to the back, and then come around to the front. As Gillian said, check out Jeff's Strategy Guide for some good ideas