Here you can digest how to use Wikipedia in bite-sized morsels. The tips listed below were created for the Tip of the day project, or the Styletips project, but are listed here by title and organized by subject area for your convenience.
Clicking the "Recent changes" link in the interaction menu on every page will give you a list of all edits in the last few minutes. If you just want to watch for changes to articles you have edited, use your Watchlist. You can add articles to your Watchlist by clicking "Watch this page" tab (starred) at the top of any article (the talk page will be auto-watched, too). You can click "Related changes" in the toolbox menu on any page to see changes made to the pages linked from the one you are viewing. And finally, you can click the "My contributions" link to view a log of your edits; if yours is no longer the edit marked with "top", then someone else has edited the page.