The NB-DSS has training material that is available for the following modules:

 Module  Manual (pdf)
Presentation (ppt)
 Data (rar)
Installing the DSS DSS Installation DSS Installation DSS_Installation
User Interface basics User Interface User Interface
Database Manager Utility and the System Manager DMU and SM DMU and SM DMU and SM
Spreadsheet Manager Spreadsheet Spreadsheet Spreadsheet
Script Manager Script Script Script
Indicator Manager Indicator Indicator Indicator
Time Series Manager Time Series Time Series Time Series
Scenario Manager Scenario Scenario Scenario
Analysis Manager Analysis Analysis Analysis
DSS Modeling Tools Modeling Tools Modeling Tools Modeling Tools

The material has a mixture of concept definitions and hands-on exercises that takes you from simple to advanced topics. Power point presentations are also available for the above modules.