Here are some Chordie songbooks that I know are autoharp compatible (I know they are harp-friendly since I edited & posted these books).
Ballads from Blondes
Silly to Sublime
"In 3" Waltz Gems
Easiest way to locate these books is to go to "All Public Songbooks", then pick "Sort Alphabetically". The "In 3" book will appear close to the end of the list since it starts with a quote symbol.
If you are playing a 12- or 15-chord instrument, you may need to transpose a bit in order to make some of these songs work for you.
Commercial music books published just for the autoharp are aimed mostly at a very narrow market niche - consequently, the range of musical selections in these publications is also very narrow. Don't let that stop you from playing anything that strikes your fancy.
Here are some notable autoharpists who have broadened the horizons of the instrument:
Penelope Houston; California Punker turned Euro-Folkie turned California Punker
The Billy Nayer Show; San Francisco rockers/performance artists/film makers
You can google up some info on these performers. Also you may want to check out the Autoharp WebRing. There are several very informative sites here plus links to good stuff: <a href="http://pages.prodigy.net/cah/autoharp/" target="_blank">http://pages.prodigy.net/cah/autoharp/</a>
Another thing that is fun to do just for shits&giggles is to go to Google News and then do a search for 'Autoharp'. Recent news articles from all around the planet will pop up for your edification and amusement.