Most browsers and servers have default values that provide fairly good performance with a minimum caching of static file content.  A little bit of coaxing can result in better performance with less traffic and less bandwidth.

There are two types of caching I discuss: static content  (*.JPG, *.JPEG, *.png, *.gif, *.ico) rarely updated and semi-static content (*.js, *.css) updated very infrequently.  The decision to cache page output (*.aspx, *.html, *.htm) long term is too dependent on application functionality decisions to discuss generically. More...