Abusing OSSEC the Countermeasures - Michael Starks showed us how to break OSSEC yesterday, today he's showing us how to protect against these attacks.
Contributing to OSSEC - A post by Daniel Cid on giving back to the OSSEC community specifically, but the principles are probably the same for all Open Source/Free Software projects.
Meet the Agent by Jason Frisvold gives a great introduction to configuring agents through ossec.conf and shared/agent.conf
These next 2 posts seem to be the "go to" source for Bigfix and OSSEC integration:
Using Bigfix for Mass Deployments of OSSEC agents for Windows by Shawn Jefferson
Monitoring your OSSEC installation with Bigfix also by by Shawn Jefferson
My contribution: OSSEC Decoders 101
And here's another just sent to the list: OSSEC to the rescue
The discussion topic of the day: 2WoO Day 3: Time to share: rules, configs, tips and tricks.