For the screen:
I've been pretty good so far, Nothing that a little huff of breath and an eyeglasses cleaning microfibre cloth couldn't fix.

For the body/keyboard:
I use a non-abrasive multipurpose cleaner called L.O.C. They come in little packets. The reason I use that is because even though it's a cleaner, it hs as harmless as water. I wipe down the keyboard and the rest of the body using that cloth, then follow it up with a microfibre drying cloth (so that the cleaner doesn't leave streaks).