How to do this?

I really love the following on this forum, and I am trying to get this also to work for me (till now without much success I may add).

Example:

(sorry Bungie for using your post as an example)

In any case after seeing / applying the categorie image template modification with success. I really can't figure this one out.

I already tried it in dreamweaver (for better overview) but still I can't do it, or it's gets too stretched or it gets oversized. So I put all the original postbit templates back, cause I really messed it up lol... Stupid me... :/

It's probably almost the same way applied as the categorie image one (3 images, etc.) but nevertheless I can't figure it out.

So if anyone could explain me how to put the images and make them fit there without too much problems, you would make me a very happy little man.

Greatings,
Michael