Greetings Cj, and welcome to the forums!
Well honestly, there are many, many answers to this questions...I think that perusing the Aperion University will help you out a great deal. Here's a link to all of the topics in the Aperion U:
http://www.aperionaudio.com/catalog/View-All-Courses,49.aspx
Here are some links to specific courses that I think will help you out:
http://www.aperionaudio.com/AperionU/how_most_sub.aspx - How to get the most out of your subwoofer
http://www.aperionaudio.com/AperionU/spl.aspx - How to use your SPL meter (You get one free with a 5.1 system)
http://www.aperionaudio.com/AperionU/multichannel.aspx - Multi channel Speaker Placement
http://www.aperionaudio.com/AperionU/what_where.aspx - What goes where
There's is more to go into, but this should be a great start. As for your receiver, you are going to want to focus on setting up the big 3. Your distance, crossover, and channel level settings. You can find out how to do this in your receivers manual, or feel free to call a guru if you'd like. We are pretty intimatly familiar with most receivers and can help you set things up right.
Welcome to the Aperion fam! Enjoy...
David Bolt
Aperion Audio Guru
www.aperionaudio.com