I’ve added links to four main national banks to the sidebar links menu. Thought it might be useful to get the information from such important institutions. Here are the links:
Federal Reserve System — for the United States of Amerca
ECB: European Central Bank - for the Eurpean Union
Bank of England — for the United Kingdom of Great Britain
Bank of Japan — for the Japan

Also, feel free to read very interesting articles about this banks from Wikipedia:
Federal Reserve System
European Central Bank
Bank of England
Bank of Japan

The People’s Bank of China is also quite important player on the world financial area, so you may find this link useful too:
The People’s Bank of China