IMO Wikipedia is good for skimming very basic, general information. To use it properly, you need to pay attention to the warnings and use the actual linked resource instead of the Wiki article itself. IMO it is a great collection of links with a general summary of them.
There are tons of issues with it, you have bias creeping in as some editors hog pages and control all content. Of course, any encyclopedia is exempt from such bias. If in doubt, check the talk pages and the logs. I admit there are tons of biased articles, but there are few quite a few non biased sources available.
Despite my many doubts about Wikipedia as the source they claim to be, it is terribly useful.