Basic Library List in Number Theory
Compiled by the Mathematical Association of America (MAA). This site sub-divides Number Theory into Introductory Texts, Expositions, Elementary Monographs, Primes and Factors, Algebraic Number Theory, Analytic Number Theory, Modular Forms, P-adic Fields, Special Topics, Cryptography, History and Biography and Classic Works.

Number Theory Books from 1996
A comprehensive, well-linked and well-maintained list of Number Theory books. The Number Theory Web, which houses this web page, contains links to pre-1996 books.

MAA books on Numbers and Number Theory
Mathematical Association of America (MAA) recently published book list. Each title is described and has a cover shot of the book, and is linked to a table of contents and a review. You can purchase books direct from the MAA here.

Research papers by János A. Csirik
Papers on Number Theory and Cryptology (PDF).