There are still many aspects of Plone that we have not covered yet -- Plone is a very complex, powerful tool.  Many interesting features are discussed in the Key Concepts section; perhaps you might want to check out the sections pertaining to homepages for folders, how to undo changes you made, or what's behind the Properties tab.

You can always come back to this site and search for issues that are puzzling you, or investigate the ever-growing FAQ.  If you can't find what you're looking for, please let us know -- we want this site to be as complete as possible and we're adding to it all the time.