Harpsichord
Big Duck's Harpsichord Miscellany, Hot Harpsichord Information Centre, Keys to the Millennium, Sounds of Harpsichords, The Difference Between Piano and Harpsichord Touch, The Virtual Vincenzo Project
Piano
Free On-Line Piano Lessons, Learn Piano Online, PianoNanny.com, Play Piano with Romeo, The Piano Player
Organ History
The Pipe Organ, a description in two parts: "The organ and how it works" and "The History of the Organ"