I would trust BtN first and foremost. However, other sites I have bookmarked are: Edgar's Name Pages:http://snipurl.com/7wjg - Good for history, not so much for meanings. Oxygen.com's Babynamer:http://snipurl.com/869q - Good (it discusses alternate meanings, always an encouraging sign), but their Hebrew names need help according to Miss Claire, one of our resident Jewish name nerds. I like the site's feature of listing similar names to the one you're looking up. Hebrew Letters:http://snipurl.com/fzpk - What Miss Claire routinely uses for Jewish names. Hungarian Names List:http://snipurl.com/kfwn - Er, the official list of Hungarian names allowed by law, with name days. However, obviously it's all in Hungarian; all you really need to know, however, is: férfi név = boy name, while női név = girl name. Bible Gateway:http://snipurl.com/2til - This is actually not a name site, but a site with multiple translations of the Bible. However, if you need an obscure translation of a Biblical name (what is the Vietnamese form of Naomi anyway?), then this is an excellent place to look it up. Patron Saints Index:http://snipurl.com/9vk9 - Another non-naming site, this is a vast collection of Catholic saints. Good for naming inspiration, if only for the unusual names that crop up, and also good for getting inspiration for character names (need a name for a pilot? Go with Joseph or Thérèse in honour of Joseph of Cupertino or Thérèse of Lisieux, both patron saints of pilots). Old Norse Names:http://snipurl.com/mrua - Viking names. You heard me! Polish Names List:http://snipurl.com/mruh - Basically the same as the Hungarian Names List, only on the Polish Wikipedia site. Obviously, only in Polish, so: imię męskie = boy name, imię żeńskie = girl name. Feminine Given Names in A Dictionary of English Surnames:http://tinyurl.com/mls6j - An excellent site for medieval female names. Divided into three eras: before 1250, between 1250-1450, and after 1450. Hawaiian Phonetic First Name Translations:http://snipurl.com/kfwr - Just what it says, and abundantly too. There are scads of translations here, but I can't vouch for absolute accuracy; certainly most of them probably aren't used by actual Hawaiians. Nevertheless, this site's interesting. Given Names c. 1450-1650:http://snipurl.com/bkk4 - Another good medieval/Renassaince name list, this time with male names included. Names in the Low Lands before 1150:http://snipurl.com/kfwp - Overview of how to construct a Germanic name that would be used in the Netherlands and Flanders at that time. At the bottom are various lists of actual names and the elements used in them. Finnish Names:http://snipurl.com/kfwq - This site has a luxury I bet many wish to have more often: pronunciations of the names listed done in actual audio by a native speaker.
The one non-"baby name" book I have is Dictionary of First Names, by David Pickering, a Penguin Reference book. I believe it's fairly good, and it has the advantage of having a lot of Indian names in it, which is a fairly rare thing to have.
Proud adopter of 15 punctuation marks; see my profile for their names.