Use these tips to evaluate the websites of organizations. Keep in mind that these are only a starting point and not guaranteed to be failsafe in every situation.
It is also important to consistently check your own biases and your own preferences for reading one source over another.
The Pew Research Center has done research on news audiences and has rated news sources by the ideological leanings of their followers. A chart of this information can be viewed at: Ideological Placement of Each Source’s Audience.
You've decided to write about how a vegan lifestyle is healthier than other diets. You are looking at news sources and find an article in Vegetarian Monthly that says that vegans have lower cholesterol than non-vegans. However, you don't include a source from Women's Running that indicates vegans usually have issues with B12 deficiency. You have chosen to only utilize sources that support your initial hypothesis. This is confirmation bias.
This is when facts are included but are misrepresented through twisted language or logic.