Web sites should be primarily filled with text. Link videos and images instead of loading onto the site.
General information( from the Google Sites Step by Step->Managing your site)
To make changes to your Site, click on "Manage Site" from the More actions drop-down menu. Using the Management Menu, you can change the way your site looks, how users navigate it, even see earlier versions.
Site ContentRecent site activity
This area shows you the history of changes made to your Site since its creation. It allows you to recover deleted pages and track down the mistakes made by others.
See all of your pages (even if they don't appear in your Navigation) and view all the changes made to them. By clicking on the Revisions number, you can compare versions or revert your page to an earlier version.
View and manage your attachments, including uploaded documents and images.