^Get Fast Lane.
Seriously, during the summer, the only way to guarantee you get on all the rides is by buying it because the lines get pretty long. It is so worth it. Leviathan and Behemoth's lines are typical around an hour, so chances are, you'd only be able to get in about 1 or 2 rides each without Fast Lane. Leviathan is usually the busiest in the morning, because people tend to go there as soon as they get in.
Personally, my favourite seat on Behemoth is the back, because you get awesome airtime on the first drop, but it does get a little rattly. Still, it's my favourite ride in the park and the airtime is heavenly. On Leviathan you either need to get the front or back, as the most airtime is found in these seats. The ride ops will assign you seats on Leviathan, but if you ask, you will almost always get the seat you want.
As for food, it's pretty meh, but you should definitely try a funnel cake, they're one of the best things in the park. For a large meal, you can try the International Marketplace Buffet, just inside Medieval Faire. The food is better than the rest of the park (though still pretty meh), it's usually pretty quiet in there. It's about 20 dollars for the buffet, I think.
The flat ride selection here is pretty good! Make sure you try Riptide (you will get soaked), Shockwave, Nightmares, Drop Tower, and Sledge Hammer (It`s pretty dull, but it`s unique!).
Finally, be warned of Time Warp, Flight Deck and Wilde Beast. Your brain may be turned to goo after riding these.
The park is really nice, and is probably the most beautiful of the Cedar Fair parks. The roller coasters for the most part may be mediocre, but Behemoth and Leviathan should make up for that! Hope you have fun!