Hi I'm very new at this and wondering you guys can please help me?

My specs are

Core 2 Duo T7700

Nvidia 8600m GT

and wifi card (most problematic) intel 4965AGN

I just want to work with sound wifi and screen. Can you tell me how to install snow leopard and how to install drivers.

I searched for months but I couldn't understand what is the solution for wifi.
Do you know how to solve it?If not can you advice me a third party wifi card works with airport for wifi using.

I will be appreciate if you guys can help me .Thanx