Thank you ma'am.
Ladyfromdallas, I'll admit that Caroline's post is very comprehensive but, if the image you want in your post is already on a webpage somewhere, just right click on it and select 'copy image' from the menu, then right click in your message and click 'paste'.
Posting an image from your PC is a little more involved, but how much work would you have to do to share a photograph with thousands, possibly millions of people before we had the internet?
A little bit of time invested in learning how to do this stuff brings great rewards, and remember, if you don't use it, you'll lose it.