http://www.thingstodo-rome.com

A nice easy-to-navigate site to start your research

http://www.romexplorer.com/

Pretty much everything you need to know about Rome...

http://www.inroma.it/indexe.htm

A useful search engine for travel information of Rome

http://www.vatican.va/

Catch up on the Pope, Michelangelo's Sistine Chapel and the world's largest number of multilingual confessionals

http://www.lonelyplanet.com/destinations/europe/rome/

Of course, the Lonely Planet...

http://www.activitaly.it/musei/index.htm

A useful guide to most museum information in Rome