I have just recently bought this game and it is really fun and nice Racing game for little over $10 (was on sale) on Steam
You can play it single player or multi-player or coop multi-player as 4 teams of 2 players or 2 teams of 4 players pretty fair review here

To play in multi-player ,if you don't have it already , you will need to download and install Games For Windows Live
Imo this game is really fun to play in multi-player with friends ,also i would recommend you to try play single player first ,to get to know the controls and cars and tracks before you jump into multi-player
Well have fun playing and hope i'll see you there soon