There are some people who mess with Wikipedia pages, but there are more a lot of people that also keep the pages clean and accurate. It takes longer for someone to mess up a page then it does for one of the wikipedia staff to fix it. Well, that's what I've read/heard. The information is pretty accurate. I do understand that it could be completely made up, but I'd rather trust wikipedia over another site made by some random "scholar".
I use wikipedia a lot. When I need information on something I usually type into Google:
xxxx=the subject
That always works for me when I need some help on something.