Just like you call the local electrical company to provide you with electricity, you call an Internet Service Provider in your area. Not sure who to call? talk to your neighbors.
Once the ISP hooks you up, he gives you a box, called a modem/router, there is a jack on the back of this router, called a RJ45, looks like an oversize phone jack, there is another on your laptop, hook the 2 together with a CAT5 cable and you should be good to go.