1) In the contacts page (Step 4) of a release. You can edit an existing schedule or create a new schedule.
2) You can browser for the list or search for a specific list you want to send to.
3) Browse list options allows you to go over your list of recipients.
4) First column of Add List page shows you
Play MPE Lists - This is the Play MPE Managed list of recipients.
My Lists - This is your own custom list that you managed on your own. This is a private list and only you or caster users from your label can access it.
Favourites - If you've added a list to your Favourites (star icon in Contacts menu), this is where it will show up.
5) Selecting any of those 3 in Step 4 will show you the lists associated with it. For My Lists, the second column will show you the labels you have access to and if those labels owns a list. If it owns a list, then you can click on the lists to show those lists.
6) You can select a list by selecting the check box next to it.
7) Once you are done selecting list/s, just click Save.