to 1. you don't need to install, unpack the zip in any folder you want. You need to reference the dll's (White.Nunit.dll and White.Core.dll). Maybe other dlls for special things I'm not sure.
use UISpy or
http://uiautomationverify.codeplex.com/ to find out all needed informations about UI Elements.
Application application = Application.Launch("path to a program");
Window myWindow = application.GetWindow("name of the window"); //get name using one of the above tools
have a look about the other classes describing UI elements in the documentation of core
ListBox, Button, and so on