Just hit the "reply" button and the editor pops up.

Down on the bottom left it has a check box "Attach File(s)". Click on that.

A "File Upload" window opens.  Click on "Browse" and find your picture and select it (double click it or "open" it). Do this for as many pictures as you want (up to 9.7 mb total).

Then click on "Upload File(s)" (down at the bottom of that window).  You can then add more pictures if you want.

Then click on "Submit Post" and you will have a post with pictures imbedded (like this).

Hope this helps,

-Dan