It is not a trustworthy source. If you want to look up something quickly but accuracy is not life and death use it. I rarely, if ever do, and never never cite Wiki as a source. I can write about physics on Wiki. Now that right there is scary.
It's not a bad start but no single source of information should be relied on. Always double check and cross check if having a close to correct answer is important.
I do not trust Wikipedia, in and of itself, but it is often a good starting point. That last section, with external links, is sometimes a gold mine of information.
