This article is from the Macintosh hardware FAQ, by Elliotte Rusty Harold firstname.lastname@example.org with numerous contributions by others.
First a word about tools: many basic household items will serve you
well when taking care of a Mac but not all. Under no circumstances
should you use a Dustbuster or other common handvac to clean
electronic equipment. Instead you need a specially designed vacuum
cleaner with a conducting, grounded nozzle. These normally cost
about $40 in electronics supply stores. Most paper towels are
adequate for cleaning computer equipment. However Scott brand towels
do have lower rag content than any other commonly available towel and
are less likely to leave paper fibers behind on your equipment.