The most interesting special page is Special:Recentchanges. It displays all edits, file uploads, page moves, deletions and other actions done in the wiki. In the menu on top it offers a collection of links to customize your display: limit the number of changes shown, the number of days or restrict it to edits to a certain namespace. You can also hide edits marked as minor (don't forget that major changes can be flagged by a user as minor anyway).
One line in recentchanges consists of several links:
Next is a flag describing the article modification type:
Following the timestamp the user is mentioned, with a link to their user page and their talk page or to their contributions (in the case of anonymous users).
Last but not least, there is an edit summary, appearing in italics, if the user submitted one when they made the edit.
If you are logged in and have JavaScript enabled, you can also try the "enhanced" view. Simply go to your Preferences and enable "Enhanced recent changes (JavaScript)"; this will make recent changes show edits divided by page rather than being listed individually. You will now see entries like the following:
Simply click the blue arrow to the left of the page name and timestamp to expand that page's recent edits just as they were on the normal style. You can turn this enhancement on and off at will, so feel free to try both to see which one you prefer.