First, you need a host. Once you have a host that has the pictures you want to post on it, find the url for the pic. If the url was http://www.tfproject.org/tfp/images/style_darkcloud/vBulletin_logo.gif, you would put the img brackets around it, like this:
[img]http://www.tfproject.org/tfp/images/style_darkcloud/vBulletin_logo.gif[/img]
And you will see this:
Just do that for each pic, and make sure to clear your cache and preview before posting.