You can get the second edition of this free 9-page Guide here. I've updated it based on the latest information from the PRINCE2 Examinations Board and from what we see happening in the PRINCE2 market place.
The Guide includes a checklist that includes all the sorts of questions people wish they'd asked at booking time but rarely do.
Anyone about to invest in PRINCE2 training is well-advised to read this first. If you are such a person, I'd be grateful if you let me know how useful or otherwise you find it.