In a blog post on April 28, AOL pointed to their new Sender Best Practices document. These are not things a sender must do in order to get mail delivered to AOL, but rather things that will help improve your reputation at AOL.
The recommendations are what I have been recommending for a while and there is nothing overly surprising in the recommendations.

• Send mail users want and expect
• Separate your mail streams
• Suggest recipients add the From: address to their address book
• Make it easy for recipients to unsubscribe
• Minimize your invalid users
• Use DKIM to authenticate email

All of these are good suggestions for sending any email to any recipient
This also adds AOL to the list of ISPs supporting DKIM. If you are not yet signing with DKIM, you should be planning the deployment path to signing.

AOL • Authentication