Hi,
First thing first, your gonna have to do soem homework. Pick up a Japan travel guide book. I find National Geographic and Lonely planet to be a good combination. Lonely planet provides you will maps, adress, and everything else you need to plan your trip. The national geographic is similar but not as "complete" as the Lonely planet one. BUT...theres tons of pictures which is kind of useful. Theres also lots of history and political stuff explained which makes it a good read.
As for the keyphrase you could try google but my best advice is, again, to pick up a 10$ conversation guide. It contains everything you need + answer people can point. The lonely planet one is again my favorite one.
As to recommendation on what to do in Japan the possibilities are almost endless. Which city do you plan to visit and what are you interested in ? You could also take a look at the other hundreds of thread like this one and seek some answers there as well.
Raisthlin
www.aujapon.raisthlin.ca