This is a quick outline of my dedicated Steam In-Home Streaming server hardware and software configuration.
Why do this? I have recently evolved my life to where I only run Gentoo Linux, so wanted a way to still play all of my Winderps-only games. This works moderately well, with few issues (only two that come to mind are a bit of mouse lag, and joystick wont work in at least one game - Evochron Mercenary).
You just need a Winderps PC capable of playing the games you want to stream with Steam installed. Of course, it should be connected to the same network as the clients to which you wish to stream.
Additionally, you'll probably want an HDMI dummy adapter, which fakes a monitor attachment (aka headless). You can use a spare monitor as well. The main goal is to attach a monitor or adapter that supports the highest resolution at which you wish to run your games.
Since this is a dedicated setup, it is recommended to set Winderps to automatically log a user in (whichever user you wish to run Steam). Streaming will not work if the screen is locked.
As such, forget RDP (Winderps built-in remote desktop), as it likes to lock the screen. VNC is recommended.
Also, you can use Cygwin for SSH access, if many of your clients are Linux.