Need a particular song or arrangement? Checkout www.sheetmusicplus.com, (opens new page) they have one of the largest selections of music books and sheet music available anywhere. Their site also has good search facilities to find what you want, AND include content indexes for most their music books.
H.S. Thompson; add'l w. Alan Skelly
Lily of Laguna
Lily of the Valley
L. Wolfe Gilbert
Lily the Pink
John Henry, Peter Michael McCarthey, Roger McGough