It looks like that our first book about OSSEC is completed and should soon be released. Andrew Hay, Rory Bray and myself *wrote it during the last few months and we also got some great external contributions (more info to come). The book is already on **Amazon, so you can pre-order it from:
http://www.amazon.com/OSSEC-Host-Based-…
*Well, Andrew did a lot of work and pushed us a lot too, so he should get more credit for it.
**The information on Amazon is not completed, but they will hopefully update it soon.