Adding application files to Visual C# IDE

Dec 8, 2008 at 1:24 PM
I'm totally new to Visual C# (and .NET in general). I found an API on CodePlex I want to use. I'm given the option of downloading the application or the source code.  If I download the application, how do I add it to Visual C# 2008 Express so that I can reference the API from my own application?  The zip file contains several files including "debug" and "release" files.

Thank you,