We intend to work on an addin for WHS sometime in the near future, but as my chief programmer still has all the workload of a typical HS sophmore, it could be a while. In the meantime:
Download and save the subsonic windows install file to any of the WHS file shares. I use the Software folder, but any folder you like is fine.
Next, remote desktop into WHS. How you ask? The easiest way in Windows is to just bring up the network display of all the computers on the network, Right-Click on your WHS and select "Connect with Remote Desktop Connection" You need to logon as Administrator and use the master password you use when opening the WHS console. Once the WHS Desktop opens, close the warning screen and open the Shared Folders on Server. Go to the folder that you stored Subsonic in and double click on the Subsonic-4.3.exe file. After the install runs you should see the green headphones tray icon at the lower right on the task bar. Right-Click on the icon to open the settings menu and select the port you want to use. NEVER USE PORT 80. Many ISP's block or use it to administer their gateway device.
If you've gotten this far:
First read:
http://monroeworld.com/android/subsonic/
Never use port 80 - ISP's often use it or block it. 8080,8081, work fine.
In Subsonic Settings/Network - UNCHECK " Automatically configure your router to allow incoming connections to Subsonic (using UPnP or NAT-PMP port forwarding)." make sure to hit the SAVE button, you may have to scroll down to see it depending on your screen size.
Manually assign a fixed intenal IP and static route to your server at the upper end of the address range of the router, out of the way of DHCP, e.g. 192.168.1.254
Set up your router manually. uPNP might work, but most often it doesn't. Learing how to do it will be a skill you'll love having as your network grows.
Check the Subsonic Control Panel to make sure it's using the right port you're going to use. I typically use 8080, 8081, etc.
Set up port forwarding in your router to direct traffic on the selected port to your server.
Learn your external IP address assigned by your ISP.
Test your setup by entering your external IP:port# to see if it connects. e.g.
http://24.88.76.61:4040/
If it works, you're good to go.