Hi
To post pics you first need to sign up to photobucket. Once you have done that and logged in you can upload photos. When you've uploaded the pics they will be displayed as a thumbmail on the main screen, role your cursor over the pic you want to post. A little box will appear that says things like Email & IM, Direct Link etc. and a box next to direct link, right click in the small box and click copy. This will copy the link to the pic.
Then when you want to post it on here type
it should look something like this but without the 3 stars ;)
[IMG]
If your still struggling let me know mate
Rich :)