Looks like you figured it out with your for-sale ad, but I'll explain it for others that may come here and try to figure it out too.
First you need to have an existing pic on the web somewhere. For example I use: www.smugmug.com
to store all my photos. Here is an example location of a photo we can use:
Once you have the photo you want selected, use your mouse and highlight the entire line and then click the "Img" option at the top and your line will then look like this:
Of course you can manually just add in the [img]&[/img] tags on each end instead, if you prefer. Once you hit 'Submit', you will then have your picture look like this:
If you do not have a place on the web to store your photo(s), you can go to freebie places like: http://photobucket.com/
...then link to them in the same manor. Of course you can do the same thing with logos, etc. where this is the URL of the logo you may want:http://www.omraoffroad.com/images/OMRAlogo_sm.jpg
Then add in the image tags like this:
Which would end up looking like this:
Hope that helps.