I'm going to step a bit further with a suggestion about your fonts. I'm older, and have poor vision. I'd suggest sticking a magnifying glass on the mainpage clickable to switch back and forth between <div> statements with larger and smaller fonts. Something like
div#normal{font-size: 20px;}
div#larger{font-size: 28px;}
div#biggest{font-size: 36px;}
and about 4 or 5 lines of Javascript to rotate through them by ID. Dead simple, just a very few lines of CSS and Javascript, and you have a very senior-eye-friendly setup.
The buttons need to be bigger, and make sure your pages have good contrast - mind things like blue text on blue backgrounds - they don't work together.
Finally, you need to have simple navigation on every page on your site. Put it at the top or down the left side, but put it somewhere.
Other than those minor points, nice site!
Bill Whedon
Serpent Systems
Dalton GA
http://www.serpentsystems.com