In this blog post I have documented the steps to install the Service Management Automation Web Service, I have also included the PowerShell command to install all of the prerequisites windows features. If you want to lean more about Service Management Automation you can find the Technet Library documents here and the Building Clouds Blog also has blogged about SMA recently.
Add-windowsfeature Web-Net-Ext45, Web-WebServer, Web-Basic-Auth, Web-Windows-Auth, Web-Url-Auth, NET-WCF-HTTP-Activation45
Watch the Cireson App store for their SMA Connector they are building for Service Manager. If you read this blog post before 9am PST 11/27/2013 you can join the SCSM.US User Group and get a preview of the connector.