If you have started working with the SQL Server 2008 CTP you may find these samples useful, available from the codeplex website.

The following sample databases are currently available for Microsoft SQL Server 2005 and Microsoft SQL Server 2008:

• The AdventureWorks OLTP database supports standard online transaction processing scenarios for a ficticious bicycle manufacturer (Adventure Works Cycles). Scenarios include Manufacturing, Sales, Purchasing, Product Management, Contact Management, and Human Resources.
• The Adventure Works DW database demonstrates how to build a data warehouse.
• The Adventure Works AS project can be used to build an AS database for business intelligence scenarios.
• The Adventure Works LT database is a highly simplified and smaller sample database which is helpful for those who are new to relational database technology.

http://www.codeplex.com/MSFTDBProdSamples