http://www.amazon.com/Practical-Unix-Internet-Security-Editi...
For people really interested in crypto there's obiously HAC [1].
For people interested in something that is updated each year: LNCS from DIMVA and RAID are quite good for understanding the problems or future problems and their solutions.
And of course phrack?
[1] http://cacr.uwaterloo.ca/hac/
http://www.amazon.com/Practical-Unix-Internet-Security-Editi...