The US Dept. of Labor has a great site for students to use to explore careers. It starts with the image above showing different school subjects. The students then click on a subject that they like, and the site links them to different careers that are similar to that subject.
It is very easy to use and provides a new way for students to explore potential careers. There is also a teacher's guide and you can look at the careers in different lists. Not every career is here, but many are and the teacher or counselor can help the student find others.
Another good site from the DOL is the Occupational Outlook Handbook. The OOH has information on different careers such as the employment outlook, education requirements, working conditions, and more.