To create a new tree, you'll need to be logged in (obviously). If you're currently editing a family tree, click on the "My Account" button on the upper right side of your screen - this will take you to a page that displays your account information (i. e. E-Mail address, user name). Below this is a list of the families you created, and on the bottom of said list a button that says "Create or import new family". If you click on this, a new family tree will be created. To switch between trees, simply go to "My Account" again and select the tree you want to work on.
