Probably 4 to 5 hours from Detroit. Check Mapblast or Mapquest to be sure. (They may estimate on the high side)
What to ride:
Beast and Son Of Beast. Don't miss these. The reports of Sonny's roughness are generally exaggerated (it was bad very early on, but got much better over the course of last year; closing weekend it was great)... but just in case, don't ride in a seat over a wheel. 2nd seat is good.
Face/Off, if you like Vekoma boomerangs/invertigos and don't mind the long lines.
Flight Of Fear, if the rumor about the OTSR's being gone is true. If it's not true, then it's still a good ride *IF* you know how to avoid being headbanged to death. (A lot of enthusiasts don't like this ride with the OTSR's and I understand why, but personally I like it anyway, and hope like hell it really is getting lapbars. YMMV.)
Racer, if you like lots of out-and-back air.
Vortex is a good Arrow looper, if a little headbangey. Anyone know if they gave this a paint job over the winter? It badly needed it.
Top Gun is good but short. It's got a nice close call with Sonny's lift hill.
Adventure Express has a lame ending. :) King Cobra I usually skip. Rugrats Runaway Reptar is new, so no opinion of that yet.