Look at this website as has already been suggested.
http://wildlife.state.co.us/Hunting/Pages/Hunting.aspx
But also request a paper copy to be mailed to your home. It is a lot more convient than looking online.
If you are going to apply for a deer hunt applications are due April 1, so you don't have much time. If you plan to deer rifle hunt you pretty much have to apply for a drawing. Over the counter tags are hard to come by for out of state hunters. You can probably be drawn for a less productive area with no preference points, but getting into a good area will require at least 3 points.
If you plan to elk hunt over the counter tags are available in 2nd season or later in about 2/3 of the state, but to get into the better areas will requre a few points. Next time I go it will be elk or nothing. I can kill a deer here in GA. It is a 3500 mile round trip and the extra $200 for elk tags vs deer is a small increase in fees.
You can pay $25 and just apply for a preference point. My BIL does this every year and only hunts every 3-4 years after he has aquired enough points to get into a good area. You can also apply for one of the best areas knowing you will never be drawn just to get a point, then apply for a lower quality area as your 2nd choice. You will probably get to hunt in your 2nd choice, and still build a point for future use. You may not kill anything, but if you want to go now it is an option.
Colorado hunting seasons and laws are VERY different than here in GA. My advice is to seek out someone locally who has gone and pick their brains. If possible find someone else who is going locally and find a way to tag along the first time.
I'm no expert, but have made several trips to Colorado during the summer months, but only 1 hunting trip after retiring in 2010. I had planned to go back last Fall, but things didn't work out for me then. Plans are on again for Fall 2013. If you have other questions I'll answer them as best I can if you'll PM me.