Posting the picture is quite simple.
You will need to use a service like photo bucket where you can upload your pictures to, then copy the link to your picture in your post.
1. Click on create a new listing button
2. Look just above the text box and you will see a box entitled IMG.
3. Put your cursor in the text box and click on IMG.
4. Now copy the link from your photo service site.
5. Click on IMG again and you're done.
When you are done you will see something like this in your text box,