The information at wikipedia is not always great, if you are an expert on the subject, say "climate change." However, it offers useful basic info.
For example, I opened a letter from LifeLock at breakfast, which claims its service will protect me from identify theft, a big headache if it happens to anyone. I thought that before I pay $10/month to protect my identity, I'd better make sure this company is a decent one. Well, wiki said it is NOT.