As I am pretty new to Visual Studio, this question may sound kinda dumb: How do I install DotNetZip library? I am using Visual Studio Express 2012 for Windows Desktop.
There is no setup for DotNetZip.
Simply download the package from its site, decompress the library somewhere in your disk and set the reference from your project to the release folder appropriate for your project type. Remember to distribute the DLL with your application.
Another simple way would be to use nuget
extension to install the library.