Microsoft has recently updated the technical documentation package for System Center 2012 Service Manager (SM12). The most interesting stuff can be found in the sm_job_aids.zip archive.
The sizer tool helps you determine possible deployment architectures and help you estimate database sizes. The tool is implemented as an Excel workbook and it is really easy to use yet very comprehensive. (SM2012_Sizer.xlsm)
Next up is some really good information on the data warehouse schema for DWDataMart. The Visio document describes Activity, Incident, Work Item, Change, Problem and System.
I am really happy for this Visio diagram since I found it quite hard to query and report against the Service Manager DW. Good stuff