Margalit Fox, the author of Talking Hands: What Sign Language Reveals About the Mind and the subject of last week's fascinating Behind The Dictionary interview, suggests these books on the linguistics of sign language:
The Signs of Language by Edward S. Klima and Ursula Bellugi
Seeing Voices: A Journey into the World of the Deaf by Oliver Sacks
The Resilience of Language: What Gesture Creation in Deaf Children Can Tell Us About How All Children Learn Language by Susan Goldin-Meadow