There are some off campus lots up and down Oak/Oconee Street between downtown and the perimeter that aren't too much of a walk to downtown or Sanford and are in the $20-$30 range for parking. There's also a park and ride at Lexington Road and the perimeter which I think runs a bus to downtown on gameday (and is free except for bus fare I think):
http://athensclarkecounty.com/2079/Park-Ride
And of course, there are some free first come, first serve lots on the UGA campus, some with shuttles that dump you at Sanford.
http://gameday.uga.edu/org/parking
The weather doesn't look too bad on Saturday, so a walk (as opposed to a shuttle) wouldn't be too bad if you're so inclined.
As far as don't miss things, downtown has a good selection of bars, restaurants, etc. Downtown favorites for my wife and me are are Last Resort Grill, Trappeze Pub, and Big City Bread (two blocks west of downtown), and Creature Comforts Brewing Company (an Athens brewery in downtown). If you get in early enough, and park along Oak St/Oconee St, try out Mama's Boy for breakfast, but be prepared to wait to be seated (I guess that goes without saying for a big gameday anywhere really), however typically when you get seated you'll be served pretty quickly. They're personal favorites primarily because everything is generally safe off the menu for my wife who has an odd food allergy. Also, if you don't mind the walk, about three blocks west of downtown on Broad Street, there's a recently opened BBQ restaurant co-owned by a Bama fan (walked in wearing a Bama hat and shirt a couple of weeks ago to pick up a catering order, and the owner remarked about my hat and alumni tag on my car, and we chatted for a while about the Wisconsin game). I haven't eaten
at the restaurant yet, so I can only vouch for them on catered events, but what I had was pretty good.
http://www.saucehouse.com/home
And of course, there's the university and Sanford Stadium too...don't miss that. :biggrin2: