1st and most important find a stump. Then pour Clorox on stump and hang camera. Deer will flock to stump and walk around like crack addicts. Next PM whild bill to help you build and maintain a deer sanctuary.... kidding aside look at aerials and topo maps for estimates. Then and most important put boots on and go scout. If it's a large tract then do small sections at a time. Absolutley nothing matches actually seeing it with your own eyes and taking notes. Take a compass