Here are a few comments about graduate education in mathematics. These comments are mostly NOT directed at students planning careers in K-12 education.
1. If you hope to find a job in which you use expertise in mathematics, you are very likely to need a graduate degree.
2. You should speak ASAP to a knowledgeable person about your goals, plans, and constraints. There are many options for graduate study in mathematics, but focused and detailed information is hard to find in writing.
3. If you are worried about financing a graduate program in mathematics (and who isn't), you should seriously consider applying to a PhD program. There is a lot of financial support for PhD students, usually through teaching assistantships. Usually, a teaching assistant makes enough money to support themselves (modestly) without borrowing. Support for Masters students is much more limited. Schools do not ask you for the money back if you leave after obtaining a Masters degree.
4. In addition to graduate programs in mathematics, consider programs in computer science, operations research, or statistics.
5. For students thinking about a PhD in mathematics, I recommend the book A Mathematicians Survival Guide, by Steven Krantz. You can find the book, with reviews, on Amazon.
ONLINE JOB RESOURCES
SIAM job search and career information - For students considering a career in mathematics
Math for America - The MfA recruits, trains, and retains outstanding secondary school math teachers to teach in New York City threw the Newton Fellowship and Newton Master Teacher Programs.
Careers in Mathematics - A Colorado State University site with several links to career opportunities for the graduating math major.
Careers and Employment - An American Mathematical Society web site with links to employment services and educational opportunities.
Graduate Job Seach Online - Developed by the University of Strathclyde to help you identify graduate vacancies and opportunities.
Teach For America - Seeking talented individuals from all backgrounds to lead the movement to end educational inequity.
PROFESSIONAL MATH ORGANIZATIONS
AMS - American Mathematical Society
MAA - Mathematical Association of America
AWM - Association for Women in Mathematics
NCSM - National Council of Supervisors of Mathematics
NCTM - National Council of Teachers of Mathematics
NAM - National Association of Mathematicians
SIAM - Society of Industrial and Applied Mathematics
SOA - Society of Actuaries