Organizing your Navigation bar
After creating all the pages for google site, I'm quite sure that you want to organize the navigation bar on the left so that is in the order that you want.
All you have to do is:
Click on Manage site, then on the new page that opens click site Layout.
Then all you have to do is simply click on edit under navigation and move your pages up or down depending on the order that you want.
Changing the Theme of the site.