Accuracy seems like the easiest of the criteria for judging an information source. Is the information presented correct, or not? It is a simple concept, but it does not necessarily have easy answer.
To evaluate accuracy:
Use multiple information sources from multiple authors, and look for discrepancies in the information they are providing.
Try to find out why there are discrepancies (if any) and which one is more correct. If there are discrepancies, you need to decide which information source(s) you trust more, based on the other evaluative criteria.
Review a research article's methodology
Is the source peer-reviewed?
Does the source list of references include scholarly sources?
Is the language or tone opinion based or does it contain facts and statistics?