What tickets are you planning to buy off season?
I agree with getting a hotel close by, although others will swear that it's worth the extra expense to be able to stay at the Hilton and just go up to your room after a late night hanging out. I've always stayed at LaQuinta, about 4 - 5 miles out, but that's because I bring my dog with me.
If you get there early enough, check on Friday to see if the parking deck across from the expo are selling any special parking passes for the show, otherwise, you're paying up to $8 a day for parking (and it re-sets if you leave and come back). I spend a ton of money on parking, but I figure that in. I "think" even the Hilton charges its guests for daily parking - and of course, there's the valet service, so you have to tip.
Bring a camera, take tons of pictures - you'll have a blast! Wish I were going this year, but I had to choose between Daytona and Tinley this year.