What should I prepare to study about calculus outside the formal class? Firstly, I'm in the military stationed overseas and I don't have access to a calculus class except online. 
My query is whether you think calculus is something that can be studied by someone who has never had a calculus class and for whom math isn't exactly their strongest subject.
What do you suggest I do to prepare?
 A: I learned calculus on my own, from textbooks. There is no reason why other people cannot do the same. Who says you have to take a course or even that a course is helpful ? Maybe its better to do it yourself.
A: Calculus is a simple subject made complicated by misrepresentation. It is essential that first you thoroughly understand what a function is. The derivative of a function is simply another function of the same variable that gives the slope of the original function. That is, differentiation is an operation on one function that produces another function called the "derivative" of the first. The derivative of a function is itself a function that has a slope so it too can be differentiated to get the "second" derivative, and so on. The questions then arise of how to obtain a derivative, the properties of the derivative, conditions for the existence of the derivative, and applications of derivatives. All are easily understood if you avoid formalism and axiomatics. The integral of a function is another function with the amazing property that it gives the area between the curve and the x axis between any two specified x values. This function is called the "antiderivative" of the original. The operation on the original function is called "integration" and you'll see why when you get to it. Integration is not at all as simple and neat as differentiation and in fact the integrals of some functions cannot be expressed in terms of the simple functions. My strong advice is to concentrate on what things ARE and are ABOUT and not on abstractions and you will see how intriguing and useful these operations and entities are.
