Adding links to top nav?

Hello.

I inherited the duty of updating this site (which is designed in WordPress):

http://www.lloydkaufman.com

I’m competent with web development from scratch (PHP, HTML, CSS, etc), but never used WordPress before. I’ve been dealing with making posts and things like that, but now I need to add a section to the site (and to the top-navigation), and I can’t figure that out at all. Can anyone help out with how to add an item/section to the top nav bar? Thanks!!!…