There are great rentals in many of the different Denver neighborhoods. The problem is they rent fast right now! I've found the best place to find them is on Craigslist. Just be cautious of ads that want you to send personal information via email and never, ever, wire money. It is best to schedule a pre-move trip out and meet possible landlords in person and inspect the rental.
There are agents that provide services who could help you. This may be something you want to consider being from out of state.
Best of luck to you!
You can also try Craigslist, Rent.com, DenverRentals.com and other sites. Be proactive and offer what you can to sweeten the pot. Such as more deposit, paying months up front, agreeing to do some of the yard work and maintenance. It is a tough rental market in the Denver area right now. Most areas are running 98-99% occupancy for the nicer rentals. Best of success in your search.j