What are some good Apache settings to use with wordpress?

Just to break cycle of “doesn’t belong here”.

WordPress basically has no specific requirements for web server itself (which doesn’t even have to be Apache), aside from permalinks.

The message you are getting seems to be performance-related and may or may not be connected to you using WordPress. For starters check if your traffic had recently increased and ask your hosting if they recommend specific Apache configuration for your hardware and traffic.