When I dynamically create a link element, and add it to the head to add a CSS file to a web page, does that file get cached?
Secondly, if it doesn't get cached, is there any way for me to have it get cached?
I'm asking browser side, if I can instruct the browser to cached the file?
It does get cached. You can control caching by modifying your site's .htaccess
file.
http://www.askapache.com/htaccess/apache-speed-cache-control.html