Stanford Unsupervised Deep Learning Tutorial (2014)
I've gone through every exercise from previous version of the stanford tutorial a few year's ago, when it was called the UFLDL tutorial.The sparse autoencoder (http://ufldl.stanford.edu/wiki/index.php/Exercise:Sparse_Aut...) exercise has been my favourite one, and I think one that is still relevant today, but became a somewhat ignored concept.