Mostly intended for modern American use, but this dictionary is often a source of valuable documentation. It gives derivations for most surnames listed, but does not cite examples with dates. Not the best source, but a good fallback. Easy to find in bookstores and some libraries.
Dunkling, Leslie, and William Gosling, The New American Dictionary of First Names, Signet Books, 1983.
Not the best source, since it is a dictionary of modern American given names, but the two authors are fine scholars, and when possible, they trace a name to its origins and give early citations. Often more important, when they know that a name is only modern, they say so! (AN)
Hanks, Patrick & Flavia Hodges. A Dictionary of First Names. Oxford University Press: New York, 1990.
-- A Dictionary of Surnames. Oxford University Press: New York, 1988.
These books contain large collections of names from throughout the world, with many variant spellings. Its main drawback is that most of the names aren't dated. It is all right to use if you use only dated entries. Recommended, if used with extreme care. (JA)
Oxford English Dictionary, Oxford University Press, 1971.
A surprising number of bynames can be documented from this dictionary. Entries give various spellings with dates, back to the earliest written citation.
NOT RECOMMENDED Yonge, Charlotte, A History of Christian Names, MacMillan & Co., London, 1884.
This can be a good reference, but must be used with care. The author often cites dates. Where she does not, her research is known to be suspect. An undated reference from this book is not sufficient documentation to register a name.