WinRT app sideloading for Enterprises or Businesses

Hi, We are developing WinRT app (win8.0)  for businesses and we need help on Side loading.

1) Understand that most Win8 Tablet are running on Win8 RT or Win8 Pro. So, we can NOT use group policy as it requires Win8 Enterprise version.

2) Understand Volume license Product Key is required. Is there any instruction or guideline on how to install it? Does the WinRT app need to embed the product Key?

your help is greatly appreciated.

Thanks