It would be hard to beat the maps issued by the ATC. If you are interested in many states, ATC has a thru hiker special every December where you can buy the entire set for half price. There are a couple of competing independent AT guides that generally have profiles and most of the information you need to thru hike the trail, but I find they are less handy than a map for finding trailheads and planning section hikes. Generally the guidebooks that come with ATC maps, are not needed having too much detail.
I used the Delorme Map guides from Virginia to Georgia for section hiking as they show the forest service roads quite accurately and there is a lot of time savings using forest service roads to get to and from trailheads. I now of a couple of areeas down south where using a forest service road saved about 50 miles and driving up and over a 5000 foot mountain (Wayah Bald)
I would also invest in a Delorme Maine guide as many of the trail access points are on private roads. Dont depend on a GPS for the private roads, the datasets are notoriously unreliable.
