I would like to add the author's avatar to posts. I am using the Avatar plug-in and it works perfectly for the Comments, but I do not know how to get it to work in the Posts. Can anyone help? Do I need to put some code into the "BYLINE:" sections of the Post/Page Info Items (in Theme Options)? If so, do you know what code? Thanks.

By the way - I am using local Avatars (it's a small family site) - not Gravatars.

You'd create the images and reference them in the post footer or other post/page info items. This will be possible in version 3.2.1 which is definitely coming this weeks, it's way overdue. There will be new info items such as author ID, author nickname, author first name, last name, etc and you'd create the images, i.e.

( 2 and 12 being the IDs of the authors )
author-12.jpg
author-2.jpg
...

Then in the post footer, i.e.:
<img src="/path/to/author/images/author-%author-id%.jpg" alt="%author-nickname%" />