Upload & Sell: Off
Good advice above, here is some more for your first couple of days. Firstly, get a copy of Fielder's Best of Colorado (http://www.amazon.com/John-Fielders-Best-Colorado-3rd/dp/0983276978/ref=sr_1_1?s=books&ie=UTF8&qid=1403882360&sr=1-1&keywords=best+of+colorado+fielder). It is the best state photography/travel book and it is on Colorado. Use it as your bible.
So, your first stop is Colorado Springs, probably the Garden of the Gods (GOG), rated last week as the best city park in America (hard to think of it as a city park). You are probably coming down I25 from Denver and you might want a quick exit off on Northgate Road to see the Air Force Academy Chapel (2nd exit down from Monument Exit). Back on I25 you take Garden of the Gods Blvd Exit (duh), west to 3oth street and left (south). Why this detail, it is well marked, well on 30th there are places soon after you turn. On the left is Mesa Road which goes up over the GOG Visitors Center and affords a great view of the park. When there is fresh snow blanketing the area it is like wonderland, not too shabby in July either in the morning light. As you might know, morning has the best light for the GOG.
Also right off 30th is a religious retreat that I believe is signed as "The Navigators". Burns me up, it is what we locals call Glen Eyrie Castle and it should be in the public domain, not some retreat. It was the home and lands of General Palmer who founded Colorado Springs (COS). Beautiful land, plenty of wildlife, and good trails which used to be open for hiking. Unfortunately, the trails are still closed because of the Waldo Canyon Fire and may never re-open. Queen's Canyon was one of the best hikes in this part of Colorado. Only way to get on the grounds is if you rent a room and can stay there: http://www.gleneyrie.org/Visit-the-Castle/Stay-Overnight. I always thought this would be cool and fairly reasonable, and sure beats any other hotel in the Springs. Convenient too, I mean, you could roll out of bed in the morning in your PJs and walk or drive over to the GOG, then come back for breakfast. I have seen more wildlife on their grounds than the rest of Colorado. So, what about the Garden?
In the Garden there are many trails and a few photographer trails too that are closed to the public (but we know where they are). My favorite is Rattlesnake Ridge, just watch out for the park rangers and snakes. (There are a few more that are more hazardous which I shouldn't say here). After the main parking area, a little up the one way loop road is a really good vantage point, one of the few that is a good evening spot too. There is a balanced rock further along the road that every one photographs, but just before it, on a dirt road on the right, marked Rampart Range, there is another balanced rock that few people visit. The Siamise Twins trail is a nice short hike, sometimes called Window Rock, because you can frame Pikes Peak in the hole through the rocks. Do stop in the Visitors Center, they have some good maps of the park. On the wall they may have for sale a picture of Kissing Camels framed by two old oaks. That is another photographers trail that common folk are not allowed up (photographers neither, but you know...)
You sound like you plan to drive south on I25 to Walsenburg, then catch Hwy 160 to the Sand Dunes. Go south a bit more to Trinidad and pick up Hwy 12, the Highway of Legends (google it) and come back to Hwy160 around La Veta - great scenic drive. At the Dunes the Great Sand Dunes Lodge is fairly reasonable and every room has a view of the dunes. Nearby is Zapata Falls and on the way along 160 is Fort Garland. There used to be, maybe still is, a ranch (Zapata Ranch?) where they would drive you out among a buffalo herd to photograph. OR, leaving GOG, you could go west on Hwy 24 instead and see many old mining towns like Victor (nice cemetery and mining trails), Cripple Creek (just went there for Donkey Derby Days) and St Elmo. So much to see and so little time... and I have not even got to the mountains. So this is a start for your trip and Darren covered the mountains well so all I will just say is"Pssst, Crested Butte" (and if go there, look for the book "Enjoying Crested Butte the Easy Way). Best advice on trails and roads for fall color and wild flowers if you spend any time there. You will be there just after the Crested Butte Wildflower Festival, they never get it right and you just may...You are welcome to PM me.