Backwoods Ethics and Wilderness Ethics are two of my favorite books.  These books, by Laura and Guy Waterman, helped shape my summer in 2002, and every day from that point onward.
Check out the Waterman Fund at http://www.watermanfund.org/

“Without some management, wildness cannot survive the number of people who seek to enjoy it,” they write. “But with too much management, or the wrong kind, we can destroy the spiritual component of wildness in our zeal to preserve its physical side.”

The books are here:
http://www.amazon.com/Backwoods-Ethics-Low-Impact-Camping-Edition/dp/088150257X
http://www.amazon.com/Wilderness-Ethics-Preserving-Wildness-Appreciation/dp/0881502561

These two books will change how you view both the back and front-country.