From the newbie guide
Posting Images: You might see other people posting images, and wonder how to do that. The easiest way is to use an image hosting service. I recommend Imgur, Photobucket, Tinypic, and Imageshack, though you have to make an account for Photobucket. Once your image is hosted it is as simple as posting the Forum or bbcode URL the site gives you [img]blahblahblah[/img]. Post that and a picture will appear. DO NOT HOTLINK. Hotlinking is when you take someone else's hosted image and post it. Not only are you using that other person's bandwidth, but 99% of pictures you find not on an image hosting service are hotlink protected. Your image will not show up for anyone but you.
It's not a rule but it's basic internet etiquette.
Stop being bad at computer.