http://blogs.msdn.com/jjameson/archive/2010/03/20/error-handling-in-moss-2007-applications.aspx
Sharepoint Administration Toolkit, ULSViewer, SPModule
http://blogs.msdn.com/dwinter/archive/2009/12/21/2009-sharepoint-toolbox-review.aspx
http://www.novolocus.com/2009/11/26/observations-on-sharepoint-2007-audit/
Shame taht the MOSS audit doesn't have a nice DatawareHouse Cube for reporting purposes
http://blogs.msdn.com/feldman/archive/2007/11/18/writing-to-the-sharepoint-trace-log-in-your-code.aspx