Diagnose possible Vacuum leak

[sconus]

Hi Everyone,
Ive had my 07 Altima 3.5 for about 2 years now and I've been very happy with her. Recently I noticed that the throttle is not as responsive as it used to be. I believe I have a vacuum leak but not sure.
The engine compartment sounds really loud, sometimes I can hear a whistling sound. It gets louder when I turn on the A/C.
Someone told me to use carb cleaner and spray around till the engine revs a bit to pinpoint the leak. Is there anywhere I can find a diagram of all the vacuum lines so I know where to look?
The car just hit 106k.

Thank everyone!