You mean into the forums?
If so:
Take your picture and upload onto a site (I use
www.photobucket.com you may have to register)
Once you upload the picture there it will automatically generate a code for you to input onto the forums or anywhere else you want to put it.
Just incase you haven't figured it out, to bring up the list of codes you click on the share button under the uploaded photo.
It should be a /img code for the forums.