How can I add pictures in this forum?
You can either use the "Insert image" button to show an image from another site or you can add one as an attachment.
And where is that button to add as attachment?!
It's in the top row of the reply page, shaped like a paper clip and right next to the smilely selections. You won't see these selections if you're using the Quick Reply at the bottom of the thread. Use the NEW REPLY button instead.
Also, scroll down a bit on the message-composition page and you'll see a section "Attach files" with a button labeled "Manage Attachments."
Separate names with a comma.