I've been working with Apache for a couple years now and am comfortable with basic administration and configuration. However, I'd really like to increase my skill set from basic administration to being a true Apache wizard. What are some must read books, mailing lists, feeds, etc. for someone looking to increase their overall skill level with Apache?
Edit - more resources:
The Definitive Guide to htaccess Techniques: Do’s and Don’ts http://www.noupe.com/php/htaccess-techniques.html
20 ways to Secure your Apache Configuration: http://www.petefreitag.com/item/505.cfm
.htaccess Email Group: http://groups.google.com/group/apachehtaccess?lnk=
alt.apache.configuration Email Group: http://groups.google.com/group/alt.apache.configuration?lnk=
The official Apache documentation is quite a good place to start.
The documentation seems to have lagged behind the browser, so one tip is to make sure to look at the Apache 1.3 documents, since these are often more complete than the Apache 2.2 ones.