Books

Droms, Ralph and Ted Lemon. The DHCP Handbook. Indianapolis: Macmillan Technical Publishing, 1999. (1-57870-137-6)

Menezes, Alfred J., Paul C. van Oorschot, and Scott A. Vanstone. Handbook of Applied Cryptography. CRC Press, 1996. (0-8493-8523-7) This book is also available electronically at http://www.cacr.math.uwaterloo.ca/hac/. It is known for being complete and rigorous, as well as cool.

Schneir, Bruce. Applied Cryptography: Protocols, Algorithms, and Source Code in C, 2nd Edition. John Wiley and Sons, 1995. (0-4711-1709-9) Also available in soft cover. This is probably the best book about cryptography if you're not all that interested in the math.

Stevens, W. Richard. UNIX Network Programming. Prentice Hall, 1990. (0-13-949876-1) A very good and extensive text on network service programming.