The information you present should be trustworthy if you want the reader to take specific actions. This requires that the facts are correct and up to date. If you aren't already an expert on the topic you are writing about then it's fairly easy to become one (Google and Wikipedia are your friend).
Do your research before starting a new article. Gather authoritative sources and don't be afraid to cite them, if applicable.
Try to give as much detail as possible and necessary. The more exhaustive your coverage of the subject, the less likely the reader will leave in search of more (and better) information.
More stringent standards apply to article topics of a medical nature!
When the health and safety of people, possibly kids, are at stake, we want to see your credentials. Preferably, you should be a medical professional and be able to back it up with proof. Again, put yourself in the position of the reader:
- Would you trust the information enough to administer the recommended product to your kids or another family member?
Chances are, if the author appears to be a cartoon character that goes by the name of "CoolTips4U" who claims in their profile to be "passionate about making money from home", you would probably refrain from following their advice.