Car shakes on idle and low rpm's
 

Okay so I just started having issues with my car, out of nowhere at a light my car started shaking and I noticed that my rpm's started dropping. This continued to happen on red lights and while in Park. When I approached red lights I put the car in Neutral and kept the revs slightly above 1k and the car wouldn't shake. Once I got home I put the car in park and it took about 5 seconds for it to start shaking again. Also the start up is kind of rough. What could be my problem? Kind of a noob with the mechanical aspect.
CAR SPECS......
04 g35 coupe
AT
148xxx miles

Motordyne throttle body reset procedure. Idle air reset.

Motordyne throttle body reset procedure. Idle reset. Do these two tests per the last page of this document.

http://www.motordyneengineering.com/manual.pdf

What exactly do I do for the throttle body reset??

Seriously? Re-read my post.

I know but what does it mean when it says, make sure the throttle valve moves during these 10 seconds by confirming operating sound.

You will hear a whine, and eventually a snap if/when the TB closes. This is not a loud snap... Rather subtle.
You could also take off the intake tube and check the TB for dirt or other clutter. Mine was caked in dirt when I checked it.