Would you like to do graduate work in economics? Here's some advice:
Prepare yourself by taking plenty of math courses. You will need a more-than-basic knowledge of calculus, matrix algebra, probability theory, mathematical statistics, differential equations, and real analysis. Here are the math courses taken by a recent undergraduate preparing for a Ph.D. program in economics:
In her first semester at graduate school, this same student reported: 'I've used every bit of math that I took--Calculus I, II, and III, Differential Equations, Foundations of Higher Math, Linear Algebra, Statistics--and I've used all of it a lot already. My advice to anyone going to an Economics PhD program is to... double major in Math and Economics...'
Economics is a social science; an economist needs to know something about psychology, history, sociology, political science, and anthropology (and preferably a bit of philosophy and biology, as well). Pick social science courses that you think are really interesting - these courses will help you discover the kind of work you want to do as an economist.
A computational revolution is sweeping economics, as cheap computing power offers the possibility of doing whole new kinds of analyses. The most widely used software includes MATLAB, SAS, STATA, R, Maple, and Mathematica. My recommendation: R (get it here). An increasingly popular programming language among quantitative social scientists is Python (get it here), which is taught in an MTSU computer science course (CSCI 3038). Some Mathematics faculty members (you need to ask the Mathematics department who they are) use the symbolic algebra packages Mathematica and Maple in their courses - it would be worthwhile to take your math classes with these instructors.