does anyone know any good websites to get materials for 3ds max?
www.cgtalk.com - I visit there often. If you go to the Discreet 3DS Max forum on that site, there’s a comprehensive thread on Mental Ray Shaders. You can also visit here: http://www.jeffpatton.net/Max7/index.html (simply amazing)
That should be a good start.
also, does anyone know how to make objects transparent in 3ds max?
in the material dialogue box, set the opacity to a lower value