This was a short little book about Princess Mia's Spring Break, and her trip from Manhattan to West Virginia to help build a house for a Habitat-for-Humanity-type charity.
I read it while I was eating at Sonic today. At 64 pages, it was a very quick read. Very good, though. I love Meg Cabot's writing style as Princess Mia.
I am now reading The Princess Diaries #5: Princess in Pink.