Sean
Best way is to get a free Photobucket (others sites are available) account, then upload the pictures to there.
To make them seen on this site, once you have uploaded the pictures, you will see to the right of the picture in photobucket under the title 'image links' some options (Email & IM, Direct Link, IMG Code and IMG Thumb). Click in the IMG Code box (to the right of the word IMG Code) and this will highlight the code and then press crtl & c on your keyboard, this will save the code to the computer clipboard.
Return to this site and then press ctrl & v and this will copy the code to your message.
That is it.
Sean