To get started with the source code version open the code in Visual Studio 2010, in solution explorer right click on the Nop.Web project and make it the startup project. Then press f5 and you will be taken to the nopCommerce installation setup.
Reff:
http://www.nopcommerce.com/boards/t/12943/how-to-start-with-nopcommerce.aspx
Beginning ASP.NET E-Commerce in C#: From Novice to Professional (Expert’s Voice in .NET)
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