I just read "Memory Lessons, A Doctor's Story" by Jerald Winakur, a geriatrician whose own father suffered from dementia. It is beautifully written, extremely insightful, and, I believe, a true inspiration to those of us who are caregivers to our elderly parents. I highly recommend this wonderful book.
When I started caregiving there were very few books on the topic of dementia. There are many more now, and it is good to get a personal recommendation.