Mnay SQL Server user don't know about the Adventure work.
The Adventure Works is a Sample Database that provided by Microsoft SQL Server and it can be downloaded from many site. For download just type free download Adventure Work 2008. you will get many site where you can download it easily.
Adventure Works has replaced Northwind & Database in SQL Server 2005.
This is only provided for the User Practice and Study. Adventure work setup contain around 4-5 database log file. but when you download it. than you will have to just run the setup.
Adventure Work 2008 setup containing the following database :