RE: Wireless router help
You don't need a wireless router at all mate. Although it would be nice to use the laptop for internet anywhere in house without needing to wire it to a modem.
However, if that's not an issue all you need is:
1) Your modem provided by virgin - connects to the wall socket as you've already described
2) An RJ45 (Ethernet Cross-Over) Cable - This will go from the modem to the laptop (Vista won't give you any problems).
It is actually recommended to use the Ethernet rather than the USB as it reduces unneccesary CPU strain.
Turn the modem off before initially connecting it to the laptop.