You need to scan and upload them to someplace where they be stored and then linked here. Use FlickR or Picasa or DropBox (all free). Once they are uploaded you can "share" the link by copying the image location link (right-click the image and select "copy image location", it varies a little between the different web storage places) and then click the picture icon
in the message toolbar when posting your message here (Insert Image URL), paste the link in there and click OK to insert the code into the message.
Like this:
This is how the code looks (NOTE - I changed the brackets [] at each end to parenthesis so you could see the code)
(img)http://www.picgifs.com/coloring-pages/disney-coloring-pages/mickey-mouse/mickey-mouse-coloring-pages-8.gif(/img)
Hope this helps! Let me know if you have questions. After you've done a few it's easy.

Like this:

This is how the code looks (NOTE - I changed the brackets [] at each end to parenthesis so you could see the code)
(img)http://www.picgifs.com/coloring-pages/disney-coloring-pages/mickey-mouse/mickey-mouse-coloring-pages-8.gif(/img)
Hope this helps! Let me know if you have questions. After you've done a few it's easy.