What part of Alabama do you live in? Check out the Sanborn Fire Insurance maps and any other old maps you can find. If you can't access them online you can probably access them at your local library or through one of Alabama's fine universities. Look for old roads, groves (thats what they used to call picnic areas) look for any "___ Grove Rd", talk to the elderly about old drive-in movie theaters, check the maps for old homesites, check old DOT maps for roads that are no longer there. Look for 19th century RR depots for possible confederate relics. One of CSA's largest arsenals was at Selma. You can buy the Official Records of the War of the Rebellion online on CD-Roms and usually get an assortment of old maps and the Southern Historical Society papers with them. In the early 20th century and earlier most schools were "one room" shcoolhouses especiall in the south.
Private yards are the easiest way to get into some good finds though. Mine your friends and business associates, don't be afraid to ask to hunt a yard but learn first how to recover a target without damaging the lawn, if it is too dry you will leave brown circles in the lawn. Fall and winter are perfect seasons for yard hunting. One thing usually leads to another..
Was the big church in town built where an old mansion used to stand? Hunt the sidewalk strips in the old part of town, they belong to the city. Watch for any place where they are tearing out and replacing sidewalks, i've never had a problem with the workers.
Mainly though... try to get into a few older lawns, old parks or old schoolyards, old RR depot sites where soldiers would have gathered to load onto trains. See if there was a Confederate hospital in your area. Maybe there was a POW camp in WW II in your area. In the 30s FDR's administration seized acres and acres of private land that people couldn't pay the taxes on (that is where most of the national forests came from). They hired workers to plant trees all over it and there are both campsites where the workers lived and old homesites where the original owners lived... I don't know about the legality in your area, you'll have to ask.
You'll find places with maps but you'll find more places by asking people about places and asking for permission from those who own land and homes.
Anything can be anywhere. Don't dismiss signals that aren't that good because they aren't that bad either... and you cannot be sure what is under your coil until you eyeball it. A good pinpointer is a must for hunting parks and lawns, as is a good hand digger. Never carry a shovel into someones yard or into a park because people will always assume you are going to do damage.
I am in NW GA but I grew up in SW GA.... that reminds me about another place you can hunt. Creeks and rivers and cypress ponds almost always had Indian campsites or villages and where you find arrowheads you may well find colonial flat buttons, colonial coins, or bells.. or gold.
HH,
Julien