The PCV is in the top of the intake manifold behind the throttle body. If you pull the airbox off of the intake and look to the left and behind the throttle body you will see the PCV. It is screwed into the intake and comes out with a quick counter-clockwise turn.
Now, for the catch can installation. Some of the kits for the 03-08 HEMI connect one hose to the oil fillter and the other to the bottom side of the airbox that mounts to the top of the intake. I have personally modified a 5.7 PCV by drilling and tapping the top of it to install a threaded barb fitting and attaching the hose from the top of the PCV to the catch can.
Some of the other kits out there have you drill the rocker covers and install the fittings. I have used several different brands. I have one from C & L that I bought from American Trucks and it works well on my 2004 Ram 1500 QC 5.7