What folder in vc++ do the property sheets go into and what is typed into orbiterdir macro sheet?
Property sheets don't go into any folder in VC++. They stay in Orbitersdk.
You add these property sheets to your project in Property Manager (if you can't see such thing you need to check a checkmark next to "Expert Settings" in Tools->Settings, but don't worry, it's used only to hide menu items and AFAIK it's only in VS2010; the VS will still talk to you in English and not in binary if you change it
).
You simply create a new empty project (and optionally add a cpp file - currently I can't check if it's required to get the configurations shown in Property Manager, or will they already show without it), next go to Property Manager's tab (under Solution Explorer) or choose View->Property Manager, right click on Debug configuration there, choose to add existing property sheet, browse to Orbitersdk\resources and add "Orbiter Vessel" or "Orbiter Plugin", right click again and add "Orbiter Debug", then you do the same for Release configuration, but without adding "Orbiter Debug" property sheet.
You can change OrbiterDir macro by expanding the tree in Property Manager, finding "orbiterroot" property sheet and editing it. You set there the full path to the Orbiter root directory. You do it only once. The next projects which will use these property sheets will have the macro already set. Additionally when you share your project with other people, the other people's macro configuration will be used, so they won't need to change anything in the project.
If you previously changed some setting in the project, now you can set them to inherit from the project parent's/defaults. Orbiter paths and settings are already set. In newer VS you only need to change the project type from EXE to DLL.
@Malky: which version of Visual Studio? In VS2010 and newer there is additional step required to get the property sheets converted to new file format.