scroll down below the message box where you type your post and... gasp... click attach files.
Much better than having to rely on a hosting site that might disappear or choose to not allow remote linking without paying all of a sudden. Especially for a site that is made to help people for many years.
you can also choose insert image. its the icon that looks like a postcard and allows you to link to an url.
How the hell do you add a picture on this forum
I have never seen such a poor forum in 32 years on message boards
None of the usually image hosting sites will work with this forum
I have tried almost everyone
Imageshack, tinypic etc