Logging in and out is pretty simple and straight forward. When you register with the forum, you are automatically logged in, so we'll start with logging out.
To log out, just go to the top right corner of the page and click log out.
To log in, go to the top right of the page. There are two empty boxes to fill out for logging in; one for username, and the other for password. Fill in the username and password.
If you want to make sure you stay logged in, and don't get automatically logged out after 15 minutes, there is a check-box underneath the username box that says "Remember me?" This is handy for when you are making long posts and it takes time to type it all out, you will want this option ON so that you don't lose what you've typed.