If you're talking your pup for a walk in the woods or for a hike, here are some basic things you should always bring with you. If you're doing more advanced hiking or backpacking, there is a lot more you have to do but I think these are pretty good basic tips!
Begin with the following:
1) Leash. No more than 6 ft in length. Attach to a carabiner for easy use.
2) Another section of rope to tie off the leash or use as a back up leash.
3) Collar with rabies tag, dog license, and a tag with dog name and your phone number. Make sure it's tight enough he can't slip out!
4) Dog brush or comb.
5) Water!! You can apparently train your water to carry their own--but make sure you do this right. I'll be researching it more later.
6) Food! If staying overnight, bring a little more than you would normally feed them.
7) Dog booties for their feet. Depending on what kind of terrain you'll be on, their pads can be seriously injured.
8) Doggy bags for their waste.
9) Dog first aid kit. Prepare their feet before, and check them after to make sure they haven't got hurt. Remember, they can't tell you!
10) Water dish