Q: Is there a good resource for identifying snakes? I found a black one on our deck, 12 ft. above the ground!
A: My best guess from the snake ID books I have is that your snake is some type of rat snake – completely harmless and probably doing a good job controlling the rodent population.
They are good climbers: see Black Rat Snake.
Remember too that all non-venomous snakes in Georgia are protected by law. Killing them is illegal, no matter how much you dislike them.
The Savannah River Ecology Laboratory has an excellent website devoted to identifying snakes, frogs and other amphibians.