I myself have just entered the fabulous world of airsoft sniping after many years of research and waiting for the good time. As we all know, sniping in airsoft isnt like in the movies (fuck you Tom Berrenger). I just found a good link to (interestingly) a WikiHow about being an airsoft sniper.
Here it is : http://www.wikihow.com/Be-an-Airsoft-Sniper
I think it's a must read to anyone wanting to become a sniper. Not only does it cover the usual 'Airsoft sniping isnt like CS'' but it also covers several important aspects that doesnt get much press : psychological factor, awareness, visualisation etc.