You will need a connector for a 2.5" IDE drive.
They will look something like this:
You can find a list of compatible connectors here (depending on how you want to connect it):
http://www.ebay.com/bhp/laptop-ide-adapter
Or, you could buy something like this, which is more convenient, if you are going to use old hard drives on a regular basis:
One of these options will let you connect a 2.5" IDE drive (which is what your picture shows) to a computer with either USB or 3.5" IDE or SATA (not shown in my pictures).