The American Foundation for the Blind continues its mission of providing tutorials to help Visually Impaired all over the world getting started using technology. Their later installment is an helpful tutorial on how to use the NVDA screen reader, from installation to navigating Windows. Here it is:

http://www.afb.org/info/living-with-vision-loss/using-technology/assistive-technology-videos/learn-nvda/1234

Enjoy it!