How to apply for CAT exam 2012?

hi all am suketh doing bcom final year in karnataka university dharwad, which is in northern karnataka , and as u know am at the last stage of my graduation, so i want to choose my next step of my student life studying MBA . so really don't know how to apply for CAT exam,,, so please any of u guide me to choose the best B schools across the country ... and please tell me what and how get prepared for this exam,,....