What is the best way to clean my white macbook without ruining it?

Check this out…
http://www.freemacblog.com/how-to-clean-your-white-macbook/

Hope that helps :)

Spray Windex lightly on 2 paper towels & wipe all metal & plastic surfaces. Dash one paper towel quickly through running water so it has a streak of moisture across it & use its moist & dry areas to wipe off & dry the Windex’s alcohol/ammonia residue. This should do it. The scant water moisture will prevent the second paper towel application from giving off dust-paper particles. Use this method on all surfaces except for the screen. Never clean your screen, it will scratch, though Radtech sells a fantastic screen cleaner cloth, I wouldn’t more than do a slight gentle dry wipe with it. Use canned air to dust your screen. Avoid talking towards your screen (to avoid saliva spots!) and for God’s sake turn your head if you sneeze!

I use iKlear. It has always worked well for me.

Clorox wipes…but don’t go near the screen with them. They’re great for the plastic parts though!

Mr clean magic eraser is what I’ve heard.