Arizona State University - Virtual Counselilng Center (STEM career depot)
This page has a good chart of resources, both for pursuing STEM careers, and for general STEM homework help. They are broken down by age group, gender focus, and STEM subject
The Fun Works
This website explores a variety of STEM careers, not just the ones you know about but also things "you never knew existed." There is also a quiz that will help you determine which careers you might enjoy.
Howard Hughes Medical Institute - Becoming a Scientist
This is a good website for people interested in Biomedical Research. Important scientists in the field offer their advice on what it takes to be one of them.
ISeek Careers: Minnesota's career, education, and job resource
Even though this website is intended for residents of Minnesota, it gives you an idea of the required qualifications and expected wages for several STEM careers. It also has good advice about what classes to take to prepare for your career, and a few suggestions on how to round out your experience through extracurricular activities and hobbies.
O-Net's list of "Bright Careers"
These careers are expected to grow faster than usual, meaning there should be a demand for qualified applicants in the near future. Click any job title to find out what the work is like, what skills you need to be qualified, and how much you can expect to get paid.
Science360.gov: Profiles of Scientists and Engineers
Learn what STEM careers are like in these video interviews of actual scientists and engineers.
WPSU / Careers in Science, Technology, Engineering, and Math
WPSU is a PBS station run by Penn State University. Their STEM careers website explores various fields through general information, video clips, and fun activities.