Call Colorado Division of Wildlife and order the big game stastics book. If gives game management unit information: how much game, how many hunters, success rates, etc. Almost all the info in that book can be had at their website, but is harder to decifer until you are familiar with Colorado. Don't be surprised when no one on here tells you to hunt "suchandsuch Mountain". Most people that have a good place to hunt found it after years of research/hunting.

I would suggest that you might consider applying for a cow tag to get you feet wet. You have to apply by April, but the chances of drawing are good in most areas, and your success rate will probably be better. Also, tags are $250 vs. a bull tag at $470 (probably will be higher next year). Find a promising area, and use the cow hunt to really scout it for the next year. Good luck