IMO you can't ever have too much scouting. That said I would scout as early and as often as you can. The early sessions would be more for learning the lay of the land. When you scouting closer to season, you should try to limit your impact on the animals. I like to scout from long distance to not disturb any potential areas I will be hunting. My goal in glassing is to learn animal travel routes through terrain and to hopefully locate an animal I want to harvest. I look at maps just for boundary references between wilderness, public, and private. I use google earth to select the areas I want to scout.