I've been there in 2007 and made the follwing trip:
First we took the flight to cleveland with united.
We rented a car and drove up to Kings Island on the first day. (about 2.5 hours drive)
The second day we did KI what can easy be done in one day.
My tip: when you take a season pass of the cedar fair group (the cheapest one) you also can enter the park one hour before the regular guests.
The third day we drove to a hotel near Holiday world (about 5 hours drive) just relax and enjoy the surrounding.
The fourth day we did Holidayworld. (i loved the park and staff)
The fifth day we drove to Beech bend (what was closed but they opened up the mouse for us). (5 hours drive)
They promissed to open the rumbler but there was a lightning that evening before what demolished some parts (also in cedar point).
In the afternoon we drove to the hotel near cedar point. (8 hours drive)
The sixth day we did cedar point including 2 more days.
It was a short but good trip what can be done again.
My advise would be skip Beech bend and do SF kentucky kingdom on your way to cedar point.
My total costs where about 950 euro all in (except dinner and souvenirs).
How a did it:
We booked the flight online by United (never use Delta it sucks) and book it months before that makes it cheaper.
We also booked the car on the airport from here just pick a rental car that fits you.(we had a Sonate V6)
For the hotels just look for a cheap one online since you just need a bed what would be enough.
We shared a room with 3 persons so we tooked a sleaping bag so we could share the beds.
Breakfast is something you will mosty do in the parks.
The season card was made at Kings island (make sure you do it early since the lines get long).
Our report can be find here:
turbolaaf.nl viewforum.php
If you needs anything else to know then just let me know.
In german is fine since i can read it normaly but writing is something i just cant do in german.
Anton.