dynamoc array size

Question

Im writing a class library and i want it to handle any type of data.

Q1: do I decelare data members as <object>varName;

Q2: how do i declare an arrya of the above?

is it <object>varName[]   or <object>[] varName

Q3: these arrary are unknown size at design time - how to i allow handle arrays that wont be sized untill the user enters there data?