1. Upload photos to a website like
http://www.imgur.com
2. Click on your photo on imgur
3. In the top right of the photo when you hover over it on your PC, there's an icon of 3 dots in a line. - Click that.
4. Brings up a menu that has the option "GET SHAREABLE LINKS" Click that.
5. A new popup comes up with 4 options. You want to click the "COPY LINK" button for "BBCode (Forums)"
6. Switch back over to you canreef post - there's a long row of icons above the text box that you type your post. Click on the square that has mountains in it. It's an insert link icon.
7. Example
8. Problem is IMGUR doesn't allow for easy resizing any more.
9. Preview your post before you post it to make sure it worked.
10. AAaaaaand... Post!