Allow me to make a few assumptions. Since you have progressed this far on this website: You know the area. You have been to the attractions. You have hiked the popular trails. You are interested in finding something new to explore.
If you don’t already have the Pikes Peak Atlas, then it’s time. In my humble opinion, this is the number one resource to exploring little known trails.
Have you read Newport In The Rockies by Marshall Sprague, yet? It has more detail on the city’s history than you need, but it explains a great deal about how and why the city grew. A lot of information on roads, buildings, people. Written in the 1980’s, his resources had experienced this growth first hand. The book Money Mountain is a similar resource on the Cripple Creek area.
The Pikes Peak Library District, http://www.ppld.org, has an amazing collection of old documents, maps and photos available to the public. Drop by the downtown Penrose Library and continue to the very back. A set of steps connects this modern library to the 1904 Carnegie Library that is now dedicated to local history. You may end up being a history geek, too. City directories, school yearbooks, brochures, maps and very helpful staff just looking to help geeks like me.
It always surprises me as to how much Google Earth can help on scouting trails. The detail from above can be zoomed in to the point of showing social trails through the foothills.