To find a CPST (child passenger safety technician) in your area follow the link below. A CPST will teach you how to install the seat and then make sure the seat is installed properly before you leave, instead of a person at a firehouse who will just might not know as much and just check to make sure it's nice and tight. Also, CPSTs know all the little details about LATCH and top tether limits, angle adjusting, can the seat touch the seat in front?, and other random little things one might not think of.
http://cert.safekids.org/get-car-seat-checked