I'm H.dryad, one of the other editors here, and I hope you decide to stay and help contribute to this amazing repository of knowledge. Although you're free to perform most tasks on Wikipedia without registering, it's highly recommended you create an account as there are many added benefits. It's private and secure and it's also free, simple, and quick to do.
Some pages of helpful information to get you started:
Remember to always sign your posts on talk pages. You can do this either by clicking on the button on the edit toolbar or by typing four tildes~~~~ at the end of your post. This will automatically insert your IP address linked to your contributions page (however, if you create an account, your IP address will be hidden and you will be able to build a custom signature that can link to your own user page), a link to this (this IP's talk) page, and a timestamp.
The best way to learn about something is to experience it. Explore, learn, contribute, and don't forget to have some fun!
To get some practice editing you can use a sandbox. If you register an account, you can create your own private sandbox for use any time. Perfect for working on bigger projects. Then for easy access in the future, you could put a link to it on your user page.
This is the discussion page for an IP user, identified by the user's IP address. Many IP addresses change periodically, and are often shared by several users. If you are an IP user, you may create an account or log in to avoid future confusion with other IP users. Registering also hides your IP address.
Welcome to Wikipedia!
button on the edit toolbar or by typing four tildes 