Alex,
In order to post pics, they must be uploaded to somewhere else on the internet first.. like shutterfly.
Go to
http://www.shutterfly.com and you should be able to sign up for free and put your pics up there. Then right click on the photo and go down to properties, right click and click on copy. Then when you post a topic, look up above this box for the "IMG" and it will ask you for a url of the pic. Put it right in there and hey presto, you're done.
Mike Ghia