Hello Shawn,

I believe it depends on the school, but I believe Khan Academy is the same if not a little more advanced.

Hope this helps.

If I were to replace school biology with khan academy biology should I take the high school biology course or should I take the biology library course or should I take both.

Within the Biology Library is the High school biology.  They are not two different courses.  The Biology Library goes deeper into the world of bio then the HS Biology course.  Also the Bio-Library combines HS and AP.

Yeah, I agree with Blue-Ice, I think that it depends on the school but I would say that Khan academy Biology is very helpful and covers every point for Biology. But depending on what school you go to determines how the comparison will turn out. 

And also I currently take the high school biology course which covers everything with that but I'm not fully sure about the Biology Libary. I suggest that you try both.

I would agree to a certain extent. I'm doing Calculus I in college and is somewhat more difficult than AP Calculus AB. This doesn't mean that AP Calculus AB is not hard by itself and doesn't prepare you well in case you later have to do Calculus I in college.