I use lots of sources. For remote scouting, I love huntdata.com's Big Game Maps DVD set ($60). For "paper" maps, I like National Geographic as they have hill shade, UTM grids (much easier to figure out than decimal degrees), landownership and elevation in feet. Problem is they don't cover the whole state. For larger scale stuff, or places out of the National Geographic coverage, I go to the USGS mapping center in Lakewood. The Forest Service maps are also essential as most will show you gates and their open and close dates (Nat Geo is good about that too).
In a week or so, I'll have my own westernhuntingdata.com up and running for stats you can't get anywhere else, plus individual unit location selections for most of the state west of I-25. Working on Oregon, Idaho and Washington also. Gonna put off the draw only states till next year.