This is a summary of books that I've found to be helpful in searching for ghost towns or abandoned mines, mostly in Colorado. Some of these may just be on my wish list.
The Mining Camps Speak by Bill and Beth Sagstetter A great and easy to read book with details of what you'll actually find at a mining site and what it is. Oddly they seem to have found it hard to find lots of things that are easy to find, like old Imperial Rand air compressors.
Rust to Riches by Eric Twitty Although a bit of a dry read it is very informative and has great details on mining equipment
Walking Into Colorado's Past: 50 Front Range History Hikes by Ben Fogelberg This is a great book with some excellent hikes. It features a lot a long the front range but also has some amazing hikes near La Junta and other areas. It details some mining info, streams, Native American petroglyphs, and other interesting features.
Ghost Towns of Colorado by Philip Varney A good ghost town book, about 10 years out of date
Colorado Ghost Towns and Mining Camps by Sandra Dallas Another good ghost town book, but 20 years out of date
Colorado Ghost Towns Past and Present by Robert Leaman This was a good ghost town book, if you want to reasearch things that aren't there anymore.
Colorado Ghost Town Stories by Sally Jennings This on my wish list as it looks like it might be more recent.
Ghost Towns, Colorado Style: Central Region by Kenneth Jessen Another book on my wish list, this one is less than 10 years out of date so some of the things that are mentioned might still be there.