People have been riding a lot of the city creek area. I have not, so this is second hand, but it sounds like its pretty good. The mornings are the best and you will likely be a little muddy into the afternoons. The east side of town would be pretty fun.
There is a pretty fun trail from the Neeley exit to the boat ramp at Massacre Rocks. The trails are not marked, but you will likely see tracks. I have heard that there is some new riding out there, but I have not been for a while and do not know for sure. As soon as we get some warmer temps for a few days it will likely be good to go. If you go, post back and tell how it was. Its a pretty fun trail.