Recommended Settings

Advanced users will probably want to use mod_rewrite caching, but PHP caching is almost as good and recommended for everyone else. Enable the following:

PHP caching.
Compress pages.
Don’t cache pages for known users.
Cache rebuild.
CDN support.
Extra homepage checks.LAnd other suggestions:

 

 

http://mashable.com/2010/07/19/speed-up-wordpress/