i strongly recommend
i find i can spend hours and learn a great deal.
as a kid i used to take an encyclopedia to the bathroom. i got screamed at much less once we built a 2nd bathroom.
what makes wikipedia great to me is the fact that it is available virtually anywhere, and that is has links, so you can zoom through topics (breadth first, vs depth first). back as a kid, it was a horror to change topics in the middle with the book format and the various volumes.
again, a strong recommendation