Welcome to the forum!
Can't say I know anything about Dover but I can help you with posting a picture.
Here is our thread on how to post a picture here on the forum using a hosting service
viewtopic.php?f=1&t=1858You should also be able to just attach the images directly from your hard drive using the "upload attachment" at the bottom of the post next to the "options"
If they are already on the internet you can just copy past the url in between the [img]your-picture-url-here[/img] tags which is a button at the top of the post window.