Elements Locations?

Hi,

I want to add an element that will display on all posts, underneath the main post image and before the blog post text. How do I do this? I can't seem to find the correct hook location. For example, "generate_before_main_content" puts the element too high. Is there a graphic or something showing the position of the elements? This would really be helpful. Selecting each one and refreshing is really tedious.

Thanks