sound system installation guidelines?

Good evening everybody. I have a few items to install for an Audio System upgrade; but don't know how to go about it. The Items that will be involved are -1 Distribution Block -2 Amps. -1 Capacitor. -1 Equalizer/Crossover -6 Speakers in Total (2 tweeters, 2 Front Door 6.5's, and 2 6x9's) -1 Subwoofer

I'm trying to connect 2 amps; 1 for the Subwoofer and the Second for Speakers. My Aftermarket Head Unit has 3 pairs of RCA plug-ins.
1) Subwoofer 2) Front 3) Rear.

How Would I connect the 6 speakers (which I'm going to rewire) to the 1st amp? Do I wire the Speakers to the Amp or Straight to the Head unit itself? Also, how would I connect the amp to the Head unit if it only has the 3 RCA plug-ins as stated above?

Any advice or suggestions are Welcomed. Thanks in advance.