One of my favorite websites is nymbler.com. You can type in a name that you like (it will give you basic meaning/origin) and then you can click a button to find names in the similiar style. It's pretty cool and a great way to figure out your naming style.
I had a book called "Beyond Ava and Aidan," or something similar, that had lists of less popular baby names. It also had them categorized nicely, for ex. vintage names, hipster names, names similar to more popular names, etc.
I like Nameberry & Baby Name Wizard. I have the book for Wizard but like the website better. I like the format she uses but the website is easier to search through. Although it irks me that Wizard has my son's name listed as female when every other website or book has listed as male or at least gender neutral. Nameberry has some real really cool lists, blogs, & discussion boards.
Re: Baby name books
BFP 1- EDD 2/09/11 Missed MC DX @11 weeks D&C- 7/25/10 BFP 2- EDD 12/22/11 Natural MC @ 5w 2d BFP 3- EDD 1/25/12 DD Josephine born 1/16/12