Tim's Trail begins and ends off of James' Trail. Traditionally it's ridden counter-clockwise, but both directions are good.
As mapped, the trail drops off the west end of James' Trail for a long straightaway descent that's fast and fun. At the bottom of the slope, the singletrack turns back and begins a rolling climb over a benched section of trail with plenty of switchbacks. You'll get a nice work-out but nothing is overly taxing, so you can enjoy the fun climb.
In the reverse, Tim's Trail opens with tight descending turns and ends with a stiff climb.