I think you will find the Expat Arrivals guide to Moving to Japan very useful. You can navigate between sections such as cost of living, accommodation and culture shock using the sidebar on the left of the screen.
If you'd like to ask anything else in particular, feel free.
I would need a few more details to be able to give you advice. Firstly, what is your nationality? Are you currently in Japan or looking to move there in the future? Would you be moving for work or other reasons, such as to be with a spouse?
Thanks for the info, that helps a lot. The best way to go about moving to Japan would be either if you can obtain employment in Japan or have a multinational company send you there for work purposes. Either way you'll need to organise the relevant visa and work permit (follow these links for more info on that).
For more general info on living in Japan you can start over here and use the menu bar on the left-hand side of the page to navigate to the various sections.
Hope this answers your question, and best of luck!