Welcome to the Wolfram Community!
I recently posted links to several resources for teaching high school math using Mathematica, which you may find useful:http://community.wolfram.com/groups/-/m/t/64865?p_p_auth=uTjdB05q
The Wolfram Education Portal
would be another great resource to add to your web site. Here visitors can find dynamic teaching and learning tools including dynamic textbooks, lesson plans, widgets, interactive Demonstrations, and more...all organized by course. Currently the site provides materials for teaching and learning algebra, calculus, precalculus, and physics I (mechanics), but more are planned for the future.
Depending on how your web site will be structured, you may also want to consider adding Wolfram|Alpha widgets
to your pages. Widgets can allow visitors to calculate answers (using Wolfram|Alpha) to certain math problems and explore mathematical phenomenon right on your web site.
Next month, we'll be hosting the Wolfram Virtual Conference for Education 2013, which is focused on using Wolfram technology for STEM education. I'd love to see you there. We'll be posting details and a link to register soon.