How do I get my email set up so that when I type a ...

The auto-completion of email addresses from your Contacts into the "To" field should happen automatically in AOL Mail if you have contacts stored in your Address Book.  Are you able to see contacts in your Address Book when you click on the folder called "Contacts"?

Automatically populating the screenname field on the sign-in page is something your browser will do if you have asked it to store it in the past.  You can also use the new check box on the sign-in screen to keep you signed in, and this will mean you have to sign-in a lot less often.