Paste the following into your .htaccess file:
# Expires Caching Start # <IfModule mod_expires.c> ExpiresActive On ExpiresByType text/css "access 1 month" ExpiresByType text/html "access 1 month" ExpiresByType image/gif "access 1 year" ExpiresByType image/png "access 1 year" ExpiresByType image/jpg "access 1 year" ExpiresByType image/jpeg "access 1 year" ExpiresByType image/x-icon "access 1 year" ExpiresByType application/pdf "access 1 month" ExpiresByType application/javascript "access 1 month" ExpiresByType text/x-javascript "access 1 month" ExpiresByType application/x-shockwave-flash "access 1 month" ExpiresDefault "access 1 month" </IfModule> # Expires Caching End #