No Disabled Souls: How to welcome people with disabilities into your life and church Jim Pierson (Standard) Absolutely the most basic book on the subject, it is chock-full of practical ideas and Biblical wisdom illustrated with inspiring stories.
God Plays Piano, Too: The Spiritual Lives of Disabled Children Brett Webb-Mitchell (Crossroad) Absolutely remarkable stories of care and wisdom. Will help anyone in the field gain an appreciation for the kids with whom they work!
Dancing With Disabilities: Opening the Church to All God's Children Brett Webb-Mitchell (United Church Press) Although it is about disabilities in the local church, it is immensely helpful in thinking about the topic. Very nicely done.
Special Education: A Biblical Approach edited by Joe Sutton (Hidden Treasure) Frankly, not a great book, but the only one which actually looks at the process of schooling those with special needs and developing Christian special ed. programs Covers quite a lot of material and is a good place to start.