If you know html, just copy the code from the 'bottom' navbar button. Then point it to a /about.htm and change the <a> content to say About, you will have to skin the page yourself, use the main section of the .tpl (very top) as template to work off. Other than that i can't really help you much more, I am busy making a new template for hfs lately.
Take a look at the source of the homepage, I made the ToG homepage using the same method.
http://www.rawr-designs.com/togYou can embed a .htm in the template itself, but i am trying to make this as simple as possible. Actually you could even use a macro to detect if the url has ?about and show the about information in place of the filelist
but thats just getting too complex, i don't know your level of programming.