Let's Make Robots!

Salvaging Parts

Hi all, 

I'm new here and wanted to know What would be good appliances or computer parts to salvage robot related parts? (motors, gears, electronics)

I saw someone take the HDD's motor, but it seems the use of it is a bit complicated, and I'm a complete noob.
Are all the motors in HDD's like the one he used or does it vary?
Thanks in advance,