Hard drive configuration: some help please..

[tal213]

i have three barracuda 7200 1TB hard drives, and need some help configuring them for PT10.

on drive#1 i already have my OS,(Windows7) PT10, and my programs=Superior Drummer, Kontakt 5 and libraries, UAD2, Amplitube and stuff like that.

drive#2 i use a different DAW Sonar X2 set up the same, but everything is 64bit.

drive#3 is blank. drive#4 (external) blank

i have read many times folks have their audio, projects/sessions, and samples on seperate drives. i'm confused as to what goes where and why and how. Can anyone shed some light or post a link, that would get me in the right direction?

thanx tal213.