Besides the DL book, there's other excellent texts that are freely available/open content on the web:
- Elements statistical Learning, Hastie et al
- Shalev-Shwartz and Ben-David: http://www.cs.huji.ac.il/~shais/UnderstandingMachineLearning...
- the late David MacKay's Info Theory
- Bayesian Reasoning in ML, Barber
- Hopcroft/Kannan (this is an older version, you can google latest: http://www.cs.cornell.edu/jeh/book112013.pdf