Setting up C# solution with multiple projects using NLog in Visual Studio

My solution in Visual Studio 2012 currently contains two projects:

• DLL
• WPF application (which requires methods of the DLL)

Both, the DLL and the WPF application, use NLog for logging. Currently each project contains the NLog DLL itself.

Here is what I don't understand:

1. It seems unnecessary to me including the identical NLog DLL in each project.
2. The DLL however shall be reusable in other solutions, i.e. somehow the NLog DLL must be contained in the DLL project.

What would be an adequate way of setting up the Visual Studio solution and/or projects?