I read the 1999 Caldecott Medal winning book - Snowflake Bentley by Jacqueline Briggs Martin. Below you will see a nice summary of the book on Amazon.com.
From the time he was a small boy in Vermont, Wilson Bentley saw snowflakes as small miracles. And he determined that one day his camera would capture for others the wonder of the tiny crystal. Bentley's enthusiasm for photographing snowflakes was often misunderstood in his time, but his patience and determination revealed two important truths: no two snowflakes are alike; and each one is startlingly beautiful. His story is gracefully told and brought to life in lovely woodcuts, giving children insight into a soul who had not only a scientist's vision and perseverance but a clear passion for the wonders of nature.
If you would like to see the story on YouTube please click on the embedded 13 minute video below.
After I read the story to them - the students would then pick out a snowflake design that I had for them. These 12 snowflake templates can be found by clicking here. You can see 2 examples of what the snowflakes templates look like below.
I hope you enjoy!