Individual Study

I am studying to be a statistics tutor and I am interested to learn other topics in statistics in addition to elementary statistics.

Thus far, I have heard of topics like behavioral statistics and Baysian statistics but have not gotten to look them over. Calculus is also done in some topics in statistics too, yes?

What I am trying to see is if there are maybe some books available online (on Amazon, for example) that are about these advanced topics in statistics. Though I am not a math major, I am interested to make it my profession to learn this subject more and more. But I would like to know just where to continue after elementary statistics education is complete.