|For more information on adding a second SOHO Router to your network, click on my name above and read my "how-to" guide on "adding a second router"|
You'll want to use the "LAN port to LAN port" scenario.
A crossover cable is recommend (and preferred) for a switch to switch connection like this, but with modern switches, isn't absolutely necessary.
I would recommend you buy a wireless SOHO Router for your garage that has 4 LAN ports so you can have wired as well as wireless connections in your garage. You would have to configure the wireless on the router in your garage to be identical to that of your house (same SSID, encryption level, and password) but as Paul said, you would disable DHCP on that router in the garage as the DHCP will pass through it from the router in the house once you have it properly configured.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.