Set up your boot order in your bios (say you have your ssd and hdd, set your ssd to boot first following your hdd). After that you won't need to touch it.
If you have an anti virus program in the form of a CD, I'd insert that first before connecting to the internet to update it.
You should be good to go to install windows 8.1. Usually I'd also update my motherboard drivers etc as well.