I attempted to attach a picture to Tom's email on the email list that shows how I add pictures to my articles. Unfortunately, it ended up in a moderation queue. So, I'll add it here instead. Click on the picture below to see it full-size.
I don't have to change whether it's "Filtered HTML" or not to add a picture. To add some HTML features, I need to edit the full HTML directly in order to make it look decent. But, for adding pictures, all I need to do is what I've described in the attached picture.
Let me know if you still have other questions and I'll see what I can do.