WordPress: Configuring Author Avatars
Author avatars use the Gravatar service, which is now default system for avatars with within WordPress. If you are already using Gravatar with your author email there is no setup required. If you haven't setup a Gravatar account, and wish to display a avatar on your blog you can register and configure this on the Gravatar website.
If you wish to use locally uploaded avatars then this can be achieved using the 'WP User Avatar' third-party plugin, which can be installed via your WordPress dashboard.
If you require any further assistance or have any questions be sure to let us know by submitting a new ticket, and we will be happy to assist.