You'll need an emulator called UAE (http://www.amigaemulator.org/) or a port like WinUAE (which comes with a frontend and is much easier), a Kickstart file for the right system (Kickstart is the name for the Rom and varied from Amiga to Amiga) and some floppy disk images for the games themselves. There's a WinUAE guide here: http://www.tweakguides.com/Amiga_1.html and a more general beginner's guide here: http://cpc464.back2roots.org/menu.htm
It's very different to modern OSes if you don't tweak around but as a modern alternative the Icarus AROS distribution (http://www.icarosdesktop.org/) provides a modern continuation of the Workbench experience.
It's very different to modern OSes if you don't tweak around but as a modern alternative the Icarus AROS distribution (http://www.icarosdesktop.org/) provides a modern continuation of the Workbench experience.