I'm very new to all of this so please have mercy on me!

Anyways, I've got a <ul> navigation bar set up, here's a live link to that:

http://www.chocolateaccents.com/test/yearround.html

I'd like to load content into a DIV that would be below the navigation bar after one of the <li> links are clicked

for testing purposes the content can just be html but later on I'd like to make it html with PHP

How would I go about this?

Thanks to anyone willing to help my sad little self.