Here is a list of some great resources you can use to learn about CNNs:
- Stanford University has a great wiki here: http://scarlet.stanford.edu/teach/index.php/An_Introduction_to_Convolutional_Neural_Networks
- Deep Learning by Michael Nielsen, found here: http://neuralnetworksanddeeplearning.com/chap6.html
- An Introduction to Convolutional Neural Networks by Jianxin Wu, found here: https://pdfs.semanticscholar.org/450c/a19932fcef1ca6d0442cbf52fec38fb9d1e5.pdf