This book, now out of print, is a detailed and interesting study of first names. The author explores trends of first names as well as giving advice on selecting a first name. The book is dated (i.e. published in the 1970's I believe) but the information is usefull and interesting none-the-less.
Like other books of this nature, Dunkling includes a statistical analysis of the most popular names. I found that analysis interesting even if its out of date now. But I especially appreciated his thoughts on the criteria for selecting a child's name. They were pragmatic and sensible.