Audio Systems: Home theater setup with older tv technology, pioneer plasma tv, pioneer receiver

Question
I  currently have a Pioneer plasma tv HD-5060 that has the separate media receiver in my study.  I did not connect the tv speakers;  instead have had a denon s-301 all in one unit hppked to the media receiver with its included spealers.   I use a cable card at present for tv.  

I now wish to replace the Denon with a "real" pioneer receiver to improve sound and utilze blue ray, gaming, etc..  Since the study is not that large I will probably just do a 5.1 system.

Please recommend best way to wire assuming the current  tv (HD-5060 Pioneer plasma and its separate media receiver), new Pioneer 5.1 home theater receiver with at least 3 HDMI ports.   Seems I would want to new receiver to "drive" everything, but I guess I may have to do something different since the tv technology is about 5 years old?  In other words Im not sure I could just plug the old media receiver through hdmi into the new receivers TV in hdmi port?

Hope this makes a little sense.  The TV still has awesome picture  so I want to keep it a while.

Answer
I'm not sure what this "separate media receiver" is. Is this something that came with the Plasma? What type of connections are on it? Is there a brand name or a model number?

As far as the question about the "best way" to wire something - I will typically feed all source devices into a receiver, and then send a single feed to the TV from the receiver.