Get an account at Flickr (http://www.flickr.com)
Upload your images to it
Select the image you want to insert into the forum
Click 'share', select 'Grab the HTML/BBCode' and then copy the code from the box.
Past all of the script into the forum message
Edit that down to [ing]http://farm7.staticflickr.com/6118/6258029663_4ea2eef500.jpg[/ing] This is all you need. Please note that I've changed the 'm' in 'img' to an 'n' for demonstration purposes.
If you want to see what the code looks like for real, just click the "Quote" button at the bottom of the post and it will insert it into your reply.
This also means that visitors to the forum can see the images and develop their interest, whereas they can't see the Pictures and Albums.
