For Data Mining I suggest the following links: 

https://deeplearning4j.org/neuralnet-overview.html

 

A numerical example to learn backpropagation in neural network

https://mattmazur.com/2015/03/17/a-step-by-step-backpropagation-example/

 

Convolutional neural network:

http://cs231n.github.io/convolutional-networks/

 

 http://iamtrask.github.io/2015/07/12/basic-python-network/

 

A good review for R and Python for data mining applications can be found :

http://www.kdnuggets.com/2015/05/r-vs-python-data-science.html

http://scikit-learn.org/stable/