What I've learned is that you don't have to be the authority on a subject to write about it. Sure, you should check the veracity of what you've written, and should read other stuff that's been written on the subject to ensure you haven't missed something obvious, but most of the time the subject matter isn't actually 'new'.

For me, an article is like teaching something on paper rather than orally.

Think of the best teacher you ever had. He / She still had to follow a syllabus; what sets apart an exceptional teacher is their capacity to present the material in such away that it interests you, and that you can understand.

Don't let your peceived lack of knowledge on a subject get in the way. Do the research, and share your findings. It can be an extremely rewarding experience.

David McKinney.