Do you know about Ronen Bekerman? http://www.ronenbekerman.com/category/tutorials/making-of/ I think if you read some Making-of you will konw more about matirials, lighting and render! It's realy very cool web-site!!! There are a lot of examples how to make your render more better! Try it and good luck!!!
P.S. Look at the viscorbel tutorial about creating matirials.