I too am a complete beginner in the field of ECU mapping and would like to learn and understand more about this subject. I am conversant with the way the internal combustion engine works from a mechanical point of view and understand the generalities of the control by various ecu's. I have studied electronics and have electronics qualifications. I guess I'm going to have to familiarise myself with new terms though.
At the moment I'm not planning on trying to map my car or anybody eles's, it is just something that has interested me for a while but never found a source of information. I'll be using some of the information in this thread to try and understand a bit more. Hoping that I can get my head around the subject if only to satisfy my curiosity. Thanks to the OP for asking the question in the first place.