You'll need a MAF adaptor, Filter of choice, most use the K&N RU-3530, and some way to put in the IAT (Intake Air Temp.) sensor. You will unbolt the MAF from the stock airbox, pull out the IAT sensor, it just rotates and then pulls out. Remove the airbox and rubber sampling tube. Then, unbolt the fender air duct if you wish, this step isn't necessary but allows a little more air to get in through the fender. Then, bolt up the MAF Adaptor to the MAF, install IAT sensor and filter and fire up. Also, this is not a bad time to clean out your intake manifolds or optimize your Throttle Body, but both of these are much more involved than installing the intake.
I think that should cover everything... Oh yea, if your MAF adaptor doesn't have an IAT inlet, you can still put an intake on. You can either grab some tubing and a T or grab the setup from BAT. Just a side note, this only applies to non-SVT cars because the SVT IAT samples from further back, in the main rubber tube, than the Non-SVT's due to the different intake setup
Hopefully this helps....
On my setup, my MAF Adaptor didn't have a hole for the IAT sensor so, since the adaptor was plastic and very thick, I drilled a hole for the MAF and took my dremel and cut back so it would sit properly in the adaptor.