2) You must have an Internet connection to use Google Maps. It works with both WiFi and/or GPRS/EDGE (2G) & /UMTS/HDSPA (3G) mobile networks. It uses both the built-in GPS and/or mobile networks for positioning.
3) To use Google Maps on mobile networks you must have a data plan with your phone carrier/operator. This can be expensive, so be careful. WiFi is generally free.
Here is a little video demonstration of Google Maps with Street View on the Nokia 5800 XpressMusic