How to open an account
Click at "log in/ create an account" at the top of the screen to the right. "Create" an account using your real name and a password of your choice. Your e-mail will not become visible to others, so you can use any e-mail you like.
If you leave messages on discussion pages, sign them with ~~~~. when you press "save page" the four signs will be automatically turned into your signature.
Use the watchlist
One of the brilliant wiki-features is the "watchlist". Every one of us is interested in different pages. To get an overview of what happens on pages you are interested in you click at "watch" in the tab-list. If you then click "my watchlist" in the command line at the beginning (where you find your name, your personal talk page etc.) you'll get a list of all the pages you have on your watchlist. You can click for a version-comparison and see what others have done with this page recently.
Use the wiki to post questions
If you have questions, do not send e-mails - use the wiki to communicate, since many of your questions will be of use to others.