It is a great amusement park, they have roller coasters, regular rides, and of course the kids rides. They also have a waterpark which is great during the summer. I also enjoyed the live shows that they have, it was great seeing the performers sing and dance.
Be sure to wear comfortable shoes and don't bring a ton of stuff with you. It's a huge park so the less stuff you have to haul around the better.
They also have a HalloWeekends that start at the end of September and go through October. They have haunted houses and people who are dressed up as well as have trick-or-treating for the kids.
There are different prices for each season and different age and height groups. It is cheaper if you go after a certain time though. Parking is $8 and food can be expensive so I recommend eating before you get there.