The flatirons area in Boulder has amazing foothills hiking. Follow this track to get a good sample of everything the flatirons area has to offer. This hike crosses Chautauqua Park and proceeds to the parking area for Gregory Canyon (you can park at the parking lot if you want a shorter trip, but a fee is charged). It then completes a steep, but short, loop through the Gregory Canyon area along the Saddle Rock Trail.
If you would like to spend the night in Boulder, there are a multitude of modern hotels, or stay in one of the Chautauquas. If you'd like to go into the mountains a bit further you can head west to Nederland for a reasonable mountain hotel. There really isn't any camping in the area near Boulder until you get near Estes Park.