Intrusion Detection with Snort
Jack Koziol
Sams
This book is a bit out of date, dealing with issues from Snort 1.8 and RedHat 7.3. I think I glanced at it for about 1 hour total. Just put it on the bookshelf next to the Snort Intrusion Detection 2.0 book which was (if u ask me) a complete reference.