"If you want a guided trip I would look into booking a seat on a comercial guided trip such as Gates of Lodore (green river) or the Yampa. Both of these trips start in the state of Colorado (Dinasaur National Monument) and finish in Utah."
I would agree with this comment. The Gates of Lodore is an awesome trip with awe inspiring views especially once you get into Dinosaur national Monument. You can easily do a 5 day trip with some great hiking right off the river, which involves Native American sites and cool water falls. Having a Guide is good for seeing everything you can but if you feel the need to Guide your own boat I would definitely do your research on the rapid and sight seeing.