To construct routes inserting origin/destination and to find places and city maps which detail particular addresses:
http://www.mapquest.com

To convert money values :
http://www.xe.com

To have information on weather  forecasts:
http://weather.yahoo.com

To translate from English and many other languages into Italian and vice versa:
http://www.freetranslation.com

For information on timetables, availability, prices of train connections throughout the Italian territory:
http://www.trenitalia.it