I also recently bought this book. When I try to compile the GadgetsAdmin project, I get the following errors:

C:\Inetpub\wwwroot\GadgetsAdmin\Categories.aspx.cs (13): The type or namespace name 'GW' could not be found (are you missing a using directive or an assembly reference?)
C:\Inetpub\wwwroot\GadgetsAdmin\Categories.aspx.cs (14): The type or namespace name 'GW' could not be found (are you missing a using directive or an assembly reference?)
C:\Inetpub\wwwroot\GadgetsAdmin\Categories.aspx.cs (15): The type or namespace name 'GW' could not be found (are you missing a using directive or an assembly reference?)
C:\Inetpub\wwwroot\GadgetsAdmin\EditProduct.aspx.c s(12): The type or namespace name 'GW' could not be found (are you missing a using directive or an assembly reference?)
C:\Inetpub\wwwroot\GadgetsAdmin\EditProduct.aspx.c s(13): The type or namespace name 'GW' could not be found (are you missing a using directive or an assembly reference?)
C:\Inetpub\wwwroot\GadgetsAdmin\EditProduct.aspx.c s(14): The type or namespace name 'GW' could not be found (are you missing a using directive or an assembly reference?)
C:\Inetpub\wwwroot\GadgetsAdmin\EditProduct.aspx.c s(15): The type or namespace name 'GW' could not be found (are you missing a using directive or an assembly reference?)
C:\Inetpub\wwwroot\GadgetsAdmin\Global.asax.cs(10) : The type or namespace name 'GW' could not be found (are you missing a using directive or an assembly reference?)
C:\Inetpub\wwwroot\GadgetsAdmin\Global.asax.cs(11) : The type or namespace name 'GW' could not be found (are you missing a using directive or an assembly reference?)
C:\Inetpub\wwwroot\GadgetsAdmin\ProductSkus.aspx.c s(12): The type or namespace name 'GW' could not be found (are you missing a using directive or an assembly reference?)
C:\Inetpub\wwwroot\GadgetsAdmin\ProductSkus.aspx.c s(13): The type or namespace name 'GW' could not be found (are you missing a using directive or an assembly reference?)
C:\Inetpub\wwwroot\GadgetsAdmin\ProductSkus.aspx.c s(14): The type or namespace name 'GW' could not be found (are you missing a using directive or an assembly reference?)
C:\Inetpub\wwwroot\GadgetsAdmin\ProductSkus.aspx.c s(15): The type or namespace name 'GW' could not be found (are you missing a using directive or an assembly reference?)
The referenced component 'GW.CMPServices' could not be found.
The referenced component 'GW.ConfigurationServices' could not be found.
The referenced component 'GW.MonitorServices' could not be found.
The referenced component 'GW.MonitorServices.Logging' could not be found.
The referenced component 'GW.SecurityServices' could not be found.
The referenced component 'GW.Web.ProductCatalog' could not be found.

How do I resolve this?

Also, when I run the complete solution, I get an error in the browser saying 'sa' is not a trusted connection. How come?

Thanks.