Music Theory Links:

Ricci Adam's   musictheory.net   Staff Paper can be printed from this site.  Also, there are lots of neat Music Theory exercises on this site.

Alan Belkin, Composer "Letter To A Young Composer"   This letter is also excellent advice for any aspiring musician. See his online books on composition.
(c) 2008 Alan Belkin

Joseph Schillinger -  Schillinger was an important composition teacher, influencing George Gershwin, Glenn Miller, Benny Goodman, and many film composers. His main works are The Schillinger System of Musical Composition and The Mathematical Basis of the Arts.  Another Schillinger Site: Schillinger's Connection to Berklee School of Music.

Classical Midi Archives   You can download midi versions of many compositions from this site. You can be a free member of this site by creating a username and a password. Then you can download or listen to up to five pieces a day.  Midi files can be imported it into Finale to get notation.  You may have to do some editing of the the resulting notation in a few places.  Most of the compositions from these pages are either public domain or used by permission.

More sites to come.