How can I remap Japanese keyboard to English?

My mom bought me a 13" Macbook Pro in Japan, running OSX 10.8. I want to know how to remap the keyboard because I'm having a hard time typing with the Japanese layout. Also, the shortcuts doesn't work. Please help. Thanks.

This is the Japanese keyboard: http://s3.amazonaws.com/dotclue.org/kybard.jpg

(eg. Change the ["] located in 2 to [@])