jrb, you can upload the pictures (upload multiple at once even) to the Gallery (see on the menu on the top) and then link to the images using the "Image" UBB code to show the picture in your post.
Those two are great. I edited your post so they show. Its a bit confusing, but if you just want to attach the picture to the post, you have to go back and edit after you attach it using the "Image" code in the "Instant UBB Code" box available when you're editing the post. Be sure to copy the URL by looking at the attached picture before editing your post, so you can just paste it in. It is easier to just post the pictures in the gallery though, as you can upload multiple at once.