Brewmaster is Valve's codename for the next version of SteamOS currently available in a preview state. SteamOS Brewmaster is based on Debian 8.1 stable.
SteamOS Brewmaster is in an early preview state where Valve is soliciting the feedback of the gaming community. SteamOS Brewmaster is available in ISO and ZIP format and is the successor to SteamOS Alchemy. Brewmaster is powered by the Linux 3.18 LTS kernel with various SteamOS patches on top.
Proxmox Server Solutions GmbH, the company behind the open-source server virtualization platform Proxmox Virtual Environment (VE), a Linux kernel-based operating system derived from Debian GNU/Linux, announced the immediate availability for download and testing of Proxmox Virtual Environment 4.0 Beta 1.
I have written a guide showing how to dual boot Windows 8 and Debian. The one thing I commend the Debian developers on is making the dual boot easy. I didn't have to choose the location of the EFI partition as the installer worked it out for itself.
Therefore having worked out that the best option is to use the network install link on the Debian homepage the rest was quite simple.