Hey Nick - success with the iPad. Here is the method.
Start new topic ( or reply to existing) Fill in title.
Write in whatever you like in the text box.
Then you will see a white cross in a small blue square where it says 'Attachments and other options'.
Tap on the blue square
This opens up, then go 'Choose File' then 'Choose Existing'.
This then opens up your iPad photos, you open up the album you want and tap on the required picture.
A miniature of it appears with '1 photo' next to it.
Then scroll down and hit 'post'.
Ta-daaa