I will continue to add to this as I get the time.
There are several ways to add an image.
1. If you have an image hosted on your own website or through an image provider such as:
You can click on the Insert Image button above the text box for new posts, insert a url and show an image in your post.

This will look like this when you are posting:
[img]http://www.archerairrifles.com/wp-content/uploads/2014/04/sumatra-2500-Carbine1-300x137.jpg[/img]