Dan how long would you say it takes for you to be able to have the skills to just pick out the beds on a map?
Ken & H/G had some great answers... I will add emphasis that it certainly varys from person to person. Once you start to find them it should get a lot easier. Part of my success is because the detective in me is facinated with figuring out why they bed where they bed, and when...
Really slowing down and rather than just noticing buck sign, taking the time to look very close and getting a feel for when and why the sign or bed was put exactly where it was put while keeping the mindset that mature bucks don't do anything randomly and everything they do has a reason will put your mind in a state of learning...
Might sound corny, but to simplify it, if you are really into the scouting and learning, rather than just doing it as a way to kill more deer, it will show in your results.