Thomas Heck's "Expanding the GFA's Online Resources" from a recent issue (Vol. 36, no. 3) of the Guitar Foundation of America's Soundboard listed some cool online resources that I know of and use and some that were new to me.
They all appear to be listed on the GFA page here: http://www.guitarfoundation.org/drupal/node/4112.
The coolest of all is the Boije Collection which I backed up to my local drive and all my backup areas as soon as I learned about it a few years ago.
I will never in my life learn a score by reading it off a screen, but I can print scores out from this collection and work on them. Given that it's mostly a 19th century music collection, it fits perfectly with the type of repertoire I work on. Thankfully, the scores are hand-written, if not facsimiles, as I really hate working on scores produced by machines. They aren't beautiful and don't look alive even though the music itself is. Also, they make learning the music harder for me and less fun. I could go on …--------------