That's really awesome that you've started. Would you want to do mobile applications next or are you sticking to web applications for now?

This might be an outdated guide, but it gives you an idea of how to build a "native" looking application using CSS, HTML and JavaScript - http://matt.might.net/articles/how-to-native-iphone-ipad-app....

You might want to try embedding some videos from Khan Academy, Youtube or the online universities. That will make your website more interesting.

Great start!