First, at home, you need the ISP connection (Adsl or Cable) via a Modem.
Adsl sometimes comes with WiFi, sometimes not.
Regardless, this is the better way to setup your LAN
Code:
modem--Router/WiFi----wired connections
|
+ ....... Wireless Connections
Your system be they Windows, Mac OS X, Linux ... need the correct driver for
the hardware installed on your systems and have nothing to do with anything
outside your box. Ethernet (ie wired) connections need the driver for your NIC card.
WiFi connections need the driver for your PCMCIA, onboard adapter, or USB WiFi adapter.
The software protocol (not the hardware) makes the connection to the
Wifi-Router. That means (once you have the right drivers, it is only a configuration issue to connect to the "available ISP".