John W. from Pittsburgh, PA on 4/23/2017 7:16:36 PM:
Check out "Crazy Guy on a Bike". Once in the site, click the Journals, then do a search for the "Great Allegheny Passage", "GAP", "C&O Canal" or "Pittsburgh to DC". Tons of journals there with photos to boot. Journals from all over the world are posted here but the GAP/C&O gets lots of entries, especially in spring and summer.
The best book to buy is "TrailBook 11th Edition: Official Guide to the C&O Canal and the Great Allegheny Passage". I highly recommend this book. Chock full of information on trail towns, where to camp/lodge, itineraries, sights along the way, etc. It also contains a water proof map which is worth it's weight in gold.