A great place to begin researching your instrument is the Grove Music entry on it. Go to Oxford Music Online or visit the library and search for Pianoforte, for example.
Books about the history of the clavichord, harpsichord, and piano, including:
Books about the history of the violin, cello, viola da gamba, and other stringed instruments. Example include:
Books about the history of the flute, clarinet, oboe, bassoon, horn, trumpet, trombone, and other wind instruments, including these: