Marketing as an expert

As I have begun to get my new autism site up and running I have noticed many sites that list "experts" how does one begin to consider themselves experts? it is interesting to look at other peoples sites to see products and services that they offer.  My friend Tony Robbins says if you find someone successful at doing what you want to do model them! No need to bake a new cake if good ones are sitting on the shelf. So far I have not found anyone doing just what I want to do. I may have found my niche.