Welcome to the IAP!!
To post a picture, go to "advanced" (box under the quick reply typing area). The advanced typing area will show up with "submit reply" and "preview post" boxes underneath. Scroll down, under Additional Options you will find "manage attachments". Click on that.
NOW, you can find the picture on your computer and follow directions to "upload" it to your thread.
Pictures need to be sized to 200kb or less, before you attempt to upload.
Good luck!!!
Ask if you have problems, many of us will answer!!