To leverage browser caching you need to edit .htaccess which will alter the HTTP headers to set expiry times for certain types of files. The following lines would need to be added to your .htaccess:
Leverage browser caching at WalkerHosting ##
ExpiresByType image/jpg "access 1 year"
ExpiresByType image/jpeg "access 1 year"
ExpiresByType image/gif "access 1 year"
ExpiresByType image/png "access 1 year"
ExpiresByType text/css "access 1 month"
ExpiresByType application/pdf "access 1 month"
ExpiresByType application/x-shockwave-flash "access 1 month"
ExpiresByType image/x-icon "access 1 year"
ExpiresDefault "access 2 days"
## End leverage browser caching ##
This should help on improving your site(s) loading speed and reduce the overall resource footprint for your account. Next step would be to look into enabling gzip compression