It's easy to find baby name books that supposedly give the meanings of names. The people who put these books together generally don't have a clue about what names really mean
. Here are some clues that will tell you if a book or web page is worth anything.
Any book which makes reference to a name as Celtic or Teutonic is cribbing off the the book "History of Christian Names" by Charlotte Yonge. This book, first published in the 19th century, is basically worthless as a source for historical information. And actually, if you look you'll find that just about every baby name book--certainly every book in the impulse buying rack at the grocery store--will have these references in them.
I've only seen two good books on the history of names in English. One is the Oxford English Dictionary of Christian Names by C.J. Withycombe. The second is Names through the Ages by Theresa Norman. Other than this, baby name books really are crap.