Decide how you will post to your list.
There are TWO ways you can submit a message to your list:
1) Compose the message in your email program and send it to the unique control- address for your list for immediate delivery.
2) Use this admin interface. Click Manage Mailings, then use the HTML editor to create your message(s) online. Schedule the day & time you want each one sent.
You can use either method at any time, but most owners quickly settle on one or the other as it fits their usage situation.
Your list's control (posting) email address can be found on your main Help page.
See this page for more details.