Like the guy above me said coinbase is great if you are in the US. LocalBitcoins is nice because you get instant gratification and don't have to give anyone your personal information. You can also try kraken if you are in Europe I have not tried them but I hear good things. You can also try the faucet sites but you will only end up with a small amount of coin from them. Some of the gambling sites will give you a small amount to start out. If you get lucky maybe you will get rich https://bitcointalk.org/index.php?board=56.0