Here is a short list of training that encapsulates the meaning of complete and vendor neutral training. No mantras of one vendor, just how to locate and report the artifacts. These trainers truly have the experience to deliver that training.
For Mac OS X Training
For Federal Law Enforcement
DCITA – Defense Cyber Investigations Training Academy
FLETC – Federal Law Enforcement Training Center
Local Law Enforcement
USSS National Academy NCFI
For iOS Device Training