Do I need a special external hard drive to use with Time Machine I am searching for a hard drive but I wonder if just about any will allow me to partition it so that I can use a part of it for Time Machine only. Thanks.
No special drive required. It only need support being partitioned as Mac OS Extended (Journaled) (also known has HFS+) -- which just about any external drive from major manufacturers support. Make sure it supports a physical connection protocol (USB 2, USB 3, FireWire, Thunderbolt, etc.) that your specific Mac happens to have and you're good to go.