How to setup for editing making 5.1 sound?

The soundtrack is just as critical as the picture. If you want a perfect picture you have to spend the money for a 10 bit or better monitor that can be calibrated and put it in a suitable room. If you want perfect sound you have to spend money on the speakers, hardware, and the room. Neither can be done on a shoestring budget.

If you are mixing for a movie then Audition is your tool. There are tools in Audition that will help you see the mix but you need an accurate and calibrated set of speakers and sufficient hardware to drive those speakers. You also need to equalize your room. This is NOT something you can do accurately without the proper room, speaker setup and hardware. Audition will do the mix using a laptop's built-in speakers but you will not be able to judge what you are hearing. You can get close if you thoroughly understand how to read the various displays for mixing in Audition and have a couple of decent speakers. To really hear what you are getting you need to spend some serious cash, scientifically place the speakers and equalize the room. If close enough is close enough for you then learn how to do the mix in Audition and don't worry about all of the expensive hardware. If you can afford the expensive hardware then Audition will use it. You just need to select it in the Audio Hardware preferences.

That is only one of the reasons that you spend several hundred dollars an hour to go to an audio mixing studio. Everything that I do for distribution is mixed at a studio. Premiere can render any Dolby or Stereo audio track you give it if the codec supports the format.