A "Preceptor" is someone that does some teaching, but does not do any teaching of new material because by the time you're with one, you should have been presented most of the material needed for safe functioning in that role. Their job is to mold you into a new Paramedic. Now most schools have a stable of preceptors that they use and contract with to send their students to. That pool of preceptors is sometimes not very large and must be shared with other programs. Most of the time, the school will find a preceptor for you. Most of the time. Sometimes you have to find your own preceptor. In my case, I could have had my school find me a preceptor, but instead, I found my own and was able to have the school approve him so that I could do my field internship near where I had moved to. What made things very easy is that he has been a County recognized preceptor for quite a few years.
So, that's the deal with this "preceptor" thing. If at all possible, I would highly suggest going to a program that will find you a preceptor and may allow you to use one you've found on your own, if they're already approved as a field preceptor by the EMS agency you'll be doing your internship through. If you have to find your own, thing can get a bit, shall we say, dicey?
