Stu you might what to read
A Basic Primer it will give you an idea what templates are all about. If you wanted to add another row then you would have to rewrite the whole template. Maybe you could use one of the menu selections to send them to another page and have all but one menu selections different. That one different menu would allow to get back home or you could see if a drop down menu with sub-menus would work. You can do this in javascript.
If you google for an uploader script, I would look in the area of "php" as there are more scripts written in php. Then you will need a another script in php to display them. Of course you will need to learn php. You can always get a better understanding of languages at
http://www.w3schools.com/ along with many other tutoral sites out there.
Hope this helps - keep us informed - we love to see the site.