Installing Hard-Drive

I just bought my eMachine T3120 last month because my old computer Processor burned out. I am wanting to install the hard-drive from the old computer in the new one, format, erase, clean, and etc. I have a place for it inside the tower. There is wiring for a Slave drive. Do I plug that stuff to my old hard-drive?

Next, How do I erase, format, clean, etc the old drive once I install it? Do I have to find drivers for it? What is the next step after I hook it up.

I am planning on running dual-boot with Linux on my old hard-drive. I am a newbie at hardware so be easy and explain with great details. Thanks in advance for all your help.