Gives more personal information than the sites above, and lets the reader know what to expect in the course of a career. The official U.S. government system of job titles and descriptions can be accessed here. Look up jobs by words in the title, by words in the description, by Standard Occupational Classification number, or by DOT number. Gives titles descriptions, skills, tasks, and demands for each job. If you need or wish to refer to the DOT, here it is in an online version.
Periodicals are an excellent source of information about potential careers.
Try Business Source Elite or Academic Source Elite for most jobs. One especially useful magazine for career information is Occupational Outlook Quarterly . It is published by the Department of Labor and includes articles on such subjects as telecommuting, outlook for college graduates, etc. The reference librarians are happy to help you.