I own the books "Teach Yourself to Play the Folk Harp" by Sylvia Woods, and "Play the Harp Beautifully" (books 1 & 2 + DVD) by Pamela Bruner.

My harp is on the larger end but from what I've experienced with these books , you shouldn't have any trouble reading them along with a smaller harp. In one of the earliest chapters of the DVD, Bruner actually demonstrates the differences between harp sizes and the ways to properly support your instrument while playing.