10' off the ground, ~4' away from the tree trunk. i usually hang my food and such about 100 away from camp.
not just for bears, our state mammal, the ringtail cat... is a determined little bugger. mice, too.
also, a good cord that will support the mass of your bag but will not cut into the tree is desired. i use Dyna Glide.
There are many stretches of the trail where you won't be able to hang your food 10' off the ground, especially on the first half of the AZT. I used an Ursack that I hung above the ground when possible but it was often still within easy reach of bears or other wildlife. However, I have no indication that any animal ever touched it (no chewing marks or anything like that). But the wildlife DID eat the straps of my trekkingpoles that were on the ground right behind my tent!