Onkyo TX-NR515 Manual (Feeling a bit overwhelmed)

This is my first dip into this stuff and this manual is massive and has SOO much information. I have a simple 3.1 setup in an apartment complex which consists of the Inifity P363's and the Klipsh RW-12D and wondering what parts of this manual are the most important?

I hope this question isnt to vauge, but my goodness I am just lost...

Heres a link to the manual for all you experts out there who might be able to help Thanks!

http://www.uk.onkyo.com/downloads/2/0/6/7/4/Manual_TX-NR515_En.pdf

Well I had my floor speakers hooked up to my older receiver without my center, then yesterday I finally got the rest of my parts and hooked up the center, then this new receiver and the sound for music just doesnt sound as good. Maybe its because I didnt listen to it loud enough and im just being dumb. It was late at night and I didnt get it to test it alot. I just want the 3.1 to sound as good as it can

No I haven't. It came with a speaker to position around the room to calibrate and all that I guess I just haven't used it yet. Been resetting everything up and that took a little bit of time.

Ok thanks. Ill try to mess with it all this weekend and see if I can't get it sounding great. Thanks