I haven't purchased a tech-related book in quite a while, but I recently picked up "Linux Server Hacks" from O'Reilly.

I must say, even an "experienced" Linux guy like myself, I found a lot of useful tips and stuff. Just little snippets of how to perform stuff.

Check it out!
http://hacks.oreilly.com/pub/ht/1 (hacks)
http://www.oreilly.com/catalog/linuxsvrhack/ (main page)
http://examples.oreilly.com/linuxsvrhack/ (example code)

-Chris