HowStuffWorks it is a great site.It has a big comprehensive database of
articles wich shows you how different things works,
from a car engine to the mind of women. The site is owned by Brian Marshall and it should be youre daily stop to learn about new things every day.The
articles are diveded into several mini articles and each article
regarding a subject is finished with many links covering the respective subject.In a way it is like wikipedia but with more pictures and detailed informations regarding each of the topic you are interested in from how forums work to how email clients work.