If your family loves the water rides, be sure to pack a change of clothes and throw them in a bag in the car. I tell the kids that we ride the water rides last so that they are not running around in wet shoes and clothes all day (yuck). We hit the water rides last, DH gets the clothes from the bag and everyone changes and enjoys the ride home peacefully
The food is great and the portions are huge (2 kids could share an adult entree). If you're a VA resident, you can pay for one day to the park and get a pass to return all summer (if you plan to come back later).
Be prepared for crowds on the weekends. Bring lots of sunblock and have fun!