Learn about careers in statistics at the American Statistical Association (ASA) website. This site provides general examples of statistical careers and also describes several fields that a statistician may work in, such as law, forestry, education, medicine, and the social sciences.
Read a wide variety of career profiles of actual people at the Mathematical Association of America (MAA) website. Most of those profiled use mathematics on a daily basis; others rely on the general problem solving skills acquired in their mathematics courses. Includes diverse careers such as teacher, biostatistician, systems engineer, and aerospace mathematician.
Career information for high school students, which is not just for high school students. In addition to providing some very nice math links, this site also provides general information about careers in math, the issue of pure vs. applied math, and choosing a university.
Career profiles of actual people working in a mathematical field. Each person's profile includes question and answer forum so that you can ask them your own specific questions. Don't forget to check out the archived profiles as well.
An index of mathematical applications provided by applied mathematicians working in industry and in government. See examples of how you can use your knowledge of Laplace transforms, ordinary differential equations, linear algebra, or other topics to investigate a real-life problem.
Mathematics that Counts, a continuing series of articles in SIAM News based on results in applied and computational mathematics research that have led, for example, to increased productivity, improvements in product design, and solutions to problems related to health and the environment.
A mentoring program, which unfortunately is intended for graduate students. It's a good thing to keep in mind, however, if you intend to go to graduate school.
The Society for Industrial and Applied Mathematics (SIAM) also provides information about careers in applied math and computational sciences. This site provides a lot of good general information about a career in math, career profiles, and a lot of good links to other sites.
There's an A-Z index of career choices in math at the Concordia College, Ann Arbor homepage. It's by no means a definitive list, but it can give you an idea of what's possible.