1) Create an account with Photobucket.com, it is free, and they don't limit you on files size
2) Upload your pictures to your library
3) When you click on the picture you'll see the following:



4) Find the Image Links toolbox, and click on IMG code (bottom of options), it will copy the link automatically (link will change briefly, showing 'copied')
5) In your post either press ctrl+v or right click and select paste
6) The link will now show in your post
7) To see what your picture looks like, click on preview and if happy with result click Submit