Need help configuring new hard drive and transferring files

I filled my existing hard drive to capacity and have purchased and installed a new 1TB WD Black drive but am struggling with where to proceed from here. My idea is to use my existing drive for running XP and installed programs and the new drive for file storage. I am not sure this is the best way but need to be pointed in the right direction if there is a better option. Specifically:

On the new drive, what is the best partition? I just selected to put it into a single partition....is this a mistake?

How do I transfer the files to the new drive?

Do I need to install XP onto the new drive even if I am planning on running it off of the old drive?

Should I leave the files on the old drive after transferring to the new, or delete them? If I delete them will it allow XP to run faster without the clutter?

How do I tell the system to save all new files etc. on the new drive instead of the old one?

I'm sure this is all very simple but I am spending way to many hours agonizing over something I don't understand, when I think someone who knows what they're doing could sit down and hash all this out in about 10 minutes!

Thanks in advance for the help,

TD