This website has an array of resources for classical guitar enthusiasts. Linked here is the page dedicated to classical guitar sheet music. Some of which, but not all, is free.
TablEdit is a program for creating, editing, printing and listening to tablature and sheet music (standard notation) for guitar and other fretted, stringed instruments, including mandolin, bass and banjo.
This homepage has been judged by many visitors as one of the most informative sites on guitar playing. It all started back in 1997 and still takes an immense amount of time to put it all together. It's a great site for instruction material and other resources that will keep you playing.
A great guitar education resource for the aspiring classical or fingerstyle guitarist. Guitar lessons, tips, free sheet music downloads and more.
A collection of free guitar music in midi and score form that is not copyright protected and is available for download.
A collection of free classical guitar scores by Giuseppe Torrisi. The site includes a list of free original pieces for guitar, arrangements, and Maestro Torrisi's CD available for free download.
Here is a good directory of free sheet music in pdf from from Delcamp.net - a site that also has a forum that is very popular in the classical guitar community.
A very comprehensive collection of free sheet music some of which is probably not legal to provide for free, so you might want to get there before the music publishers do ;)
A Web site with lots of sheet music downloads of new and traditional repertoire for the classical guitar provided by Sveinn Eythorsson from Iceland.
An extensive collection of classical guitar music in tablature
ClassClef is a non profit website dedicated to all classical guitarists seeking free sheet music, gpx and midi.
A large collection of traditional, folk, and roots music with lyrics, chords, sheet music and midis. Includes Bluegrass, Old-time, Irish, Scottish, Country, Children's songs, Christian, Session tunes etc. Also large collection of music theory, reference and research works.
8notes.com has a handful of free classical guitar sheet music. They have music for not only classical guitar, but also various styles and for different instruments. The link provided takes you to their page dedicated to classical guitar sheet music.