[Plugin: jQuery Colorbox] Colorbox not working

Hi, I am having trouble with colorbox and found the following information in the forum relating to someone with a similar problem:

Make sure that your theme uses the wp_head(); function in the HTML head-tag.

I don’t know how to find the HTML head-tag in my theme to check to see if the code is there. I am using the Georgia theme by StudioPress. I’m not sure if I can post a link as the site is still under development and the page on which I am using the gallery is still only in draft form and not published. Grateful for your help.

http://wordpress.org/extend/plugins/jquery-colorbox/