Ssd and hdd combo with duel boot OS

Have a p8z77 v pro mobo, I7 3770k cpu, xfx 7950 gpu, 1 Plextor 256gb ssd, 2wd 750gb hdd and 1 wd 1tb hdd. win 7 & 8 duel boot config. Win 7 on 256gb ssd plugged into 6b sata port win 8 on 1 750gb hdd plugged into 3gb sata port Am waiting for my ocz revodrive max iops 480gb ssd, pci express. Have appx. 300gb data on win 8 of which the libraries us apprx. 100gb. Win 7 I use for programs like Microsoft word. Can anyone give me a step by step setup to maximize performance with both hdd and ssd. Would there be any setup problems with duel boot OS. Have 2 6gb sata ports and 4 3gb sata ports. One other ting, when I add up data from all folders including hidden folders, should be around 30-35gb. My computer says 197gb. Where did the extra data com from and why cant I fid it on the ssd, any suggestion's.