[guerito]

I always shoot raw and I definitely recommend you doing so too, if you are to shoot a wedding. Especially if your camera is new, you're not 100% familiar with the settings and you're not a seasoned pro, you could easily get the white balance wrong and ruin the whole set of pictures. Raw lets you set the white balance when you interpret it, that is when you load it into your image editor or convert it to TIF or JPG. That means you can set the camera to "Auto WB" and forget about it. You can concentrate on DOF, exposure, light and shadow, facial expressions, pose of the subjects, wedding guests and other distracting elements in the background and so on and so on. There is still enough left to worry about - "we don't need no steenking white balance."

BTW raw needs a lot more space on the card, see that you have a computer close by to unload the card in between the shooting sessions. Or bring several cards. Would be a pity to run out of storage in the middle of the wedding, wouldn't it?