Dumpwoody is an upper middle class area about thirty minutes(without traffic) from ATL. You would take I-85N to GA 400 North and get off of either the Dunwoody exit or you can go to the Northridge Rd exit and go in from there. It really is a nice place,with a whole lotta high dollar homes. Check out some of the restaurants on Hwy 9 between Abernathy and Dunwoody Club Dr. I think there are a few good eateries over there. As for sights, Dunwoody is bordered by the Chattahoochee River and off of Northridge you can get to the state park that runs by the river. Veddy nice. Also you an go north on Roswell Rd. and turn left just after you cross the river and follow it around to a nature conservancy. Along the river there is a nice park and also the Atlanta Rowing Club has a bunch of skulls there. Pretty neat to check that out.
If you need hotels, I believe that there are several right off of I285 and 400 which is about a stones throw from Dunwoody. I dont know them offhand. Sorry.
As for nightlife, just head south on Hwy 9,aka Roswell Rd ( from Abernathy Rd) and there are a bunch of bars on either side of the road just before you get to 285. If you were to keep on going south on Roswell, you will eventually come into the Buckhead district(about 5-6 miles from 285). Lots of bars and clubs to keep you busy.
I do most of my work around there, so if you have any other questions, maybe I can help ya out.
Edit: You asked if it was safe. Yeah, its about as safe as you can get. No troubles at all going out at night or anything unseemly.
Peace
Lounatik