Photo’s couldn’t view at the same time

My photos were stored in my Nikon camera. I have approximately 40 photos on it. Then I decided to transferred them to my email inbox. But the problem is couldn’t view them all at the same time.
So I decided to select them one by one. Those chosen pictures will be saved to a folder. And through that folder, I’ll view those photos in their thumbnail sizes. But I don’t really know how to do that. What should I do?
