CLR Inside Out: The Performance Benefit of NGEN
Surupa Biswas publishes an article on NGEN in MSDN Magazine.
It discusses many aspects on how to make the best use of NGEN.
Check it out.
https://msdn.microsoft.com/msdnmag/issues/06/05/CLRInsideOut/
(Surupa is the Program Manager for CLR NGEN team.)