Here you can view the existing lists, with their list code and list GUID.
The button "Actions" far to the left allows you to edit a list or to delete it.
Let's see all the options you have when editing a list:
When clicking on "Edit", you will be redirected to a page whose upper part looks like this:
To start with, you can give the list a name and indicate a company (e.g. if you are an adverstisement agency and you are managing the mailings of several clients).
Then you have 5 tabs; let's see them in detail: