^What Elissa and Bill said.
Plus, after 6 pm crowds will get significantly lower. Between noon and 2 pm there'll be sign at each ride op booth telling you how long the park will be open on this day. The minimum is 6 pm, but reality says that it's never under 7 pm in the summer. We've even had a 9 pm day.
If you want to go to the Food Loop Restaurant, you'll have to make reservations. The line for the reastaurant can be up to one hour plus waiting for your food. Otherwise I recommend the Irish Pub in the irish kiddie area. It's awesome and has a very low line after 1 pm. The other option is what we did for the first time: Ignore the big restaurants, go snacking over the course of the day and go for a larger dinner. There are so many litte snack shacks we've missed so many times - it was well worth it.
Oh, and download the app. Wait times are almost always accurate and so it helps you a lot. It also shows you where you are and how you have to walk to get to your desired attraction.
Any other particular questions?
Beast|Mystic Timbers|Wodan|Twister|Phoenix; Dive:
Flug der Dämonen|GateKeeper; Launch:
Top Thrill Dragster|Karacho; Floorless:
Flying Turns; <200ft:
Expedition GeForce|Maverick; >200ft:
Magnum XL-200; >300ft:
Millennium Force; Mine:
Colorado Adventure; Boomerang:
Steel Vengeance|FLY|Formula Rossa|Blue Gemini|Colossos|Kennywood|Hersheypark