Adding Some HTML
 

How would I add some HTML that went into every posting e.g. between the posting and the byline footer. I'd like this to just happen to every post and not be input by the person writing the blog post.

You can add HTML into all the boxes at A. Theme Options -> Post/Page Info Items

Instead of just adding your post info items add, i.e.

YOUR HTML HERE<br /><br />POST INFO ITEMS HERE