Here are some very good videos... You should really take a look at these...
http://www.youtube.com/watch?v=3IMTNomhg-E
http://www.youtube.com/watch?v=doh7BbpC5V4
http://www.youtube.com/watch?v=9eA1wmKfEAQ
http://www.youtube.com/watch?v=asq05S5Ijbw
http://www.youtube.com/watch?v=gVh67rScKjA