Click this and when you're on its homepage, look for and click the "Join this Group" button on the middle of the right side. And that's it! Once you join the group, the header of the group will be added to your Groups list on your own homepage. You can click that if you want to submit your entry. You can do so by posting a photo on the "Post to a Group" button at the right side of your Inbox and click "photos" and upload your photos or entries..