Hi, Phyllis. You posted your question in exactly the right place.
Lynda.com is an online software tutorial resource that I recommend highly. Generally a course is topically divided into five to ten minute segments that you can watch in sequence or pick topics of specific interest to you. And I see that they have a course on the D800.
Membership is by the month or by the year with unlimited usage during the membership period.
Jon Kandel A New York City Nikonian and Team Member Please visit my website and critique the images!