The best and most well-known BS detector is the aptly named CRAAP test. Don't laugh! It's an acronym that stands for "Currency, Relevance, Authority, Accuracy, and Purpose." It applies to all kinds of sources from news to research. Flip through this presentation to see how it works.
Some websites attempt to fool you into thinking they are more authoritative than they really are with tricks like these.
Keep an eye out in your browser's address bar for sneaky additions to more authoritative domain names, like ".com.co" here:
Don't trust a website based on a name alone. Despite the naming convention, there's actually no such newspaper as the "Denver Guardian," seen here:
Likewise, despite the apparent reference to a channel number, there's no such cable news channel as "Now 8 News," either.