Roger that, Blacksheep!
Kickflapper, I don't think the forum allows pasting images in, or attaching them. That's not uncommon, because attachments have to be stored, and that puts a burden on the forum host.
As Blacksheep mentioned, you need to choose a photo hosting site, load your images there, and then you paste the links in your posts here. Photobucket is one, and I use it, though recently, they appear to have increased the number of ads that they show to non-account holders, whether you go to Photobucket, or even just viewing a linked image. I have an account, so I don't see the ads, but I know that our web filter here at work has a harder time handling Photobucket since last summer.
There are other hosts, though, and I think you can even link photos you have uploaded to Facebook, if you use Facebook.
If you take a look in the Forum Technical Assistance forum:
http://cs.finescale.com/fsm/feedback_help_and_testing/f/22.aspx
You'll find other threads and discussions about inserting images in posts here.
Hope that helps!