It's not meant to be the definitive guide and I don't profess to be an expert. But I've had two very excellent holidays in Japan and used the system quite extensively so have some experience.
I intended for this to be an open thread, but suggest that replies are limited to those that add information (or correct posted stuff) to keep it a concise guide.
Which Japan Rail Pass should I get?
Note that you MUST buy the pass before you arrive in Japan.
First decision is whether to get a one, two, or three week pass. The time period is in consecutive days starting from the time you hand over your exchange voucher once in Japan.
There are various types of pass, but your choice is basically between the main JR pass (covers you for JR services throughout the country) or one of the passes offered by...