It comes with a power cable, you will need to buy a sata data cable.   Pretty straightforward.  There's one 3.5" hdd bay it slides in there.
Hi there I've just ordered an r11 with a 2tb ssd, I'd like to put a 8tb hdd in aswell, are there already cables for the hdd to plug straight into when I get it or do I need some more cabling and is this easy to do? This will be my first desktop so I'm just getting the hang of this 
Aurora R11, HDD upgrade, #2