You must log in to this site first (see login at the top) and your account will be synced with the forums. Then you will be able to log in to the site (which logs you in to both) or just the forums.

First, you can submit more than just a blog entry. You can submit a book page, images and videos, or a poll for others to vote on something. You can also create your own Team.
This is all done from the "create content" section (except for the Team creation); the link can be found once you log in. A new menu will come up with your username at the top.
Simply click the create content and select which type of content you would like to submit.