^Hi Darrin.
Ask these questions like these in the General Help forum, where I will move
your post to into its own thread.

The question is whether you want to "attach a picture from your computer", or whether you want to link to an
image on a site like Flickr.

For the first option, have a read of this thread.

For linking to a hosting site like Flickr, pick a good sized image of about 2000 pixels and find and copy its
BBCode. Paste the BBCode into a post her on AP. For other sites, copy the image location and post here.