What sort of training are you looking for? Here is my FAQ on selecting a provider.
How to select a training provider
Ask for a resume for the instructor, what are his qualifications? What boards and commitees has he sat on regarding the topic? What professional papers has he published?
Ask for references and actually call some of them, most training managers will be happy to give you feedback on a class and trainer.
What is the work history of the trainer? Is he just reading a canned course or is he really an expert in the feild with real life experience?
Look at the company, and the courses they offer. A red flag is a company that provides CPR, ladder safety, forklift, and oh yeah, we do arc flash training too. Look for a company that also provides arc flash surverys, engineering studies and other power system services. You want a real expert.
Your training should fit your specific needs, an Electrical Contractor has very different training needs than a large manufacturing plant. There is no such thing as a one size fits all training course. I used to customize every class I did based on the clients needs.
If the trainer does not ask you questions about your existing ESWP's, arc flash syudy, PPE program and request a pre training meeting, thats another red flag. Unless it is an open enrollment course, which is usually not as effective as one at your facility made just for you.
Remmember your training is a much larger investment than the course fee, you are setting a culture in motion that will determine how you do everything, from your PPE program, to your hazard analysis method, to your disipline program for non-compliance.
One more thing, if someone says they offer a 70E "Certification" course, run.