Has anyone added fog lamps to their Xterra that didn't have them from the factory? I would like to know what hardware I need to complete the installation and if it's an easy installation.

Welcome to the forum.

You should do a search as this has been asked and answered several times. Try the link below for a start.

http://www.xterraownersclub.com/ubb/ultimatebb.php?ubb=get_topic;f=78;t=000761#000000

try web page . thats where I got the info for installing Piaa's on my '03. If your not prewired. If you are they got factory lights too.

i suck at adding hyperlinks

from srpage's link:
"I just ordered them from www.yournissanparts.com. They gave me a price of 239.99 plus shipping, I found the site from a Frontier board along with a 10% discount code: clbttn."

I ordered the kit about 3 weeks ago and the discount code was still valid FWIW.