Generally speaking,while you do need general education, intelligence, knowledge of currentevents, etc., for general transcription, there is no special school ortraining required for general transcription.
Legal transcriptionalmost always requires, in addition to all of the general transcriptionskills, previous legal (usually law office) experience. You may findcourses called "legal transcription" courses. These may or may nothelp you in obtaining legal transcription work.
School/training is required for medical transcription.