The first thing I'd do is call Colorado Parks & Wildlife (303-297-1192) and get the 2012 Colorado Big Game hunting booklet, assuming you don't have one already. It's pretty easy to read thru it and get an understanding of all the procedures for tags, points, units, etc. THEN I would get on the website and start looking. You want to get to the Statistics section and start checking there. All the units are listed by species and have total number of tags, allocation between Res/NRs, number of applicants and points needed.
Once you've narrowed it down, call the regional office in the area you pick and talk to them. Usually pretty helpful. At least this way you can narrow the field and get some kind of idea of where you want to start. Everyone here on this site will give you lots of advice and help, but you will have to be a little more specific.
Good Luck!!