To add a picture it must be publicly accessible on the Internet. To use it use this code: [img]http://www.example.com/image.jpg[/img]
This forms an in-line picture such as this:
To add a link you can either directly insert the URL such as here: http://www.airport-data.com/,
Or you can use this code: [url=http://www.example.com]URL Text[/URL]
This forms a link like this.
You must have "BBCode" and "HTML" enabled in your preferences.