Yea, it's pretty easy, so it shouldn't take you long. The idea is to create an image map over the image. This way you can specify various coordinates in the map which reflect the coordinates on the image and choose what parts link where. Here are some links to help you out.
Image map: http://www.w3schools.com/tags/tag_map.asp
I've never tried this way: http://www.ehow.com/how_4499356_make-image-map-using-photoshop.html
I usually do it through dreamweaver: http://help.adobe.com/en_US/dreamweaver/cs/using/WScbb6b82af5544594822510a94ae8d65-7c13a.html
You can do it by hand the way the first link shows, and get the coordinates in photoshop
If you have it in a background image in your css (I'm assuming you have your content in a div) put your content in a instead and wrap the span in an tag Example: <a href=""><span>CONTENT</span></a>