Determine the range of values for which you are finding the area between the two curves. Either this will be given explicitly or represented as a labeled area of a graph. In the latter case, you must determine the x-values that define this bounded area. Calculate the points of intersection of the two functions.
Within the domain defined by the x-values you calculated or were given in the previous step, determine which of the two functions is "on top" (has a greater y-value) in the bounded area of the graph.
Create a new function by the subtraction of the "top" function from the "bottom" function.
Determine the area under this new function by taking the definite integral between the x-values defining the bounded area of the graph (as determined in Step one).
Solve the integral using a technique appropriate to the function, or by referring to your table of common integrals. You have now determined the area between the curves.