Not sure what you were checking out, but if it has to do with scaling images then you don't need to do that, the forum software does it for you. [img]http://www.google.com/intl/en_com/images/srpr/logo1w.png[/img] looks like this:
But you can make the image any size you like by specifying the width. Here's a smaller width, notice that if you click on it it grows to it's original size, [img=50]http://www.google.com/intl/en_com/images/srpr/logo1w.png[/img]:
And here's a larger width, if you click on it it shrinks to it's original size: [img=400]http://www.google.com/intl/en_com/images/srpr/logo1w.png[/img]:
[thumb] is the same as [img] except that by default it scales the image to be 100 pixels wide, [thumb]http://www.google.com/intl/en_com/images/srpr/logo1w.png[/thumb]:
--Percy