What can you tell me about fashion journalism?

I would like to know:
-what it involves and what qualifications i need from school and university.
-An online website where i can read a fashion column or an example of what people who are fashion journalists write.
-Roughly the highest and lowest amount i would earn if i chose this career path.
-And do you have to know lots about fashion or can this be learnt as i qualify?

Complex question but thanks in advance for answers that even answer one point of my question!!!

Scarlett xxx