Where are you looking to find a job? Most places would like some experience, but it is certainly not required. Different regions vary a great deal on how they provide EMS - some through paid fire, some volunteer fire, some paid EMS, some volunteer EMS, or any combination of the above. Find out where classes are held and talk to the people there. They can give you a good idea of the type of work availabe in your area.
If you have more questions about the whole process, try posting in the EMS forum here on SDN. Lots of experienced EMS peeps from different areas of the country in there.