I was going to do a writeup on WannaCry but then I found these excellent links.
"This blog post is split up in two parts: 1 for users, 1 for companies/businesses. Most tips however are interchangeable and can be applied on most environments"
Some official Microsoft guidance
"Stop blaming the customers who drown in the endless torrent of repairs needed to plug the holes in your shoddy products"
"Simply put, specialized devices, and a critical need to maintain stability in healthcare environments can sometimes mean that patches are forgone or postponed for lengthy testing."
In-depth analysis of WannaCry
Keep it safe and remember... never pay the ransom!