Programs are basically free if you volunteer or work for a fire department or ambulance service. If not then it's the tuition cost at the community college, probably a couple hundred $$ altogether. The education is solely based on emergency response, first aid, understanding the emergency services system (dispatcher, fire, EMS, air rescue, radio communications, etc). There are clinicals where you ride along with an ambulance and also do time in the ER, basically practicing patient assessments and basic EMT skills (vitals, immobilization, hemhorrage control, O2 delivery, etc). The patients you see as an EMT range from birth to 100+ years, they have medical illnesses, traumatic injuries or a combination of the two...some of the most complicated and challenging scenarios you'll encounter. I'm not sure what you mean by "how long do they take"? If you're talking about the length of an EMT course, it's dependent on the state guidelines. Most are about 150-200 hours combined classroom and clinical.
Hope that helps. I'm sure people much more knowledgable than me can give more precise info on the costs involved and length of class time. I've had a paramedic card for almost 20 years and would never want to lose it.