Download and burn an Ubuntu 10.10 Live CD. Boot it and check if you can see your SATA HDD using GParted which is under "Administration"
It'll probably show up as NTFS, unformatted or something if it's anew drive. (I'm assuming you're attaching a new SATA drive to your existing system)
Hit the install icon if you're happy. You'll end up with GParted in the partitioning section of the install. Re-select the new SATA HDD for the install and let Ubuntu decide how it wants to partition it; swap files, root, etc. (You can play about with partitioning at a later date once you're more familiar with Linux, I'd leave it for now... Maybe next install
Ubuntu will install Grub2 boot loader and allow you to select either Ubuntu or whatever was on your already installed disk.
Hope that helps, Welcome to LQ and...