Other contributors have said "Are there any jobs hiring for ages 15 and up?" is the same question as "What jobs can a 15-year-old get?".
You can work in an: office, grocery store, retail store, restaurant, movie theater, baseball park, amusement park, or gasoline service station.
You generally may not work in: communications or public utilities jobs, construction or repair jobs, driving a motor vehicle or helping a driver, manufacturing and mining occupations, power-driven machinery or hoisting apparatus other than typical office machines, processing occupations, public messenger jobs, transporting of persons or property, workrooms where products are manufactured, mined or processed, or warehousing and storage.
In addition, you may not work any other job or occupation declared hazardous by the Secretary of Labor.
Different rules apply to farms, and individual States may have stricter rules.
http://www.youthrules.dol.gov/jobs.htm
America's Job Bank. http://www.ajb.dni.us: Has sites for employers and job seekers. About 1.5 million job listings. User can develop an on line career account with resume, etc. Links to latest job trends, employer profiles and online training and information resources. Free.
America's Career InfoNet. http://www.acinet.org/acinet Sponsored by the U.S. Department of Labor, America's Career InfoNet contains information about the General Job Outlook, Wages and Trends, Employer Search, State Profile and Career Exploration. Also has a Resource Library.
Job Corps. http://jobcorps.doleta.gov: Job Corps is the nation's largest residential education and training program for disadvantaged youth. It is a full-time, year-round residential program that offers a comprehensive array of training, education and supportive services, including supervised dormitory housing, meals, medical care and counseling.