While I'm not a regular reader, the few times I looked at its treatment of various crackpottery, I found it reliable and well-sourced. As with any wiki, remember to follow the sources linked in articles. as these will inevitably be more thorough.
I find it overall pretty reliable but as always it pays to verify facts using more than one source. It is also often very sarcastic so keep that in mind.
I've found www.metabunk.org to be handy and seemingly quite good at debunking crackpot claims/pseudoscience.