Here’s a CSS technique that I didn’t know about, and perhaps you didn’t either. To center an element on the page — like the image above — just set the margins to “auto.” This only works on block elements, so you’ll need to modify the “display” value for images.
If you want a fixed width site running down the center of the page:
Handy. Again, this may be obvious to a lot of people, but I apparently managed to avoid learning about it for the last six years. It was difficult to remain that oblivious, but I’m tenacious that way.