Here are some NLP classes:

* Oxford Deep NLP Lectures https://github.com/oxford-cs-deepnlp-2017/lectures

* Stanford Natural Language Processing with Deep Learning http://web.stanford.edu/class/cs224n/syllabus.html

* Georgia Tech Natural Language Understanding https://github.com/jacobeisenstein/gt-nlp-class

* Georgia Tech Deep Learning For NLP in PyTorch https://github.com/rguthrie3/DeepLearningForNLPInPytorch

And some books:

* Natural Language Processing with Python https://www.amazon.com/Natural-Language-Processing-Python-An...

* Foundations of Statistical Natural Language Processing https://www.amazon.com/Foundations-Statistical-Natural-Langu...

I wish I had more ideas for applications using techniques like this, otherwise I would probably spend much more time researching natural language processing.

Instead, I did a simple project on searching using language processing and just read Foundations of Statistical Natural Language Processing [1], which is not too difficult, and Speech and Language Processing: An Introduction to Natural Language Processing, Computational Linguistics and Speech Recognition [2], which is a pretty heavy read but a great reference. I was able to find a used copy of the second book for $0.30.

I also put a bit of study into articulatory phonetics and speech recognition as part of a graduate study-abroad, which is an interesting field on its own, but I always wanted to come back to computational linguistics.

[1] http://www.amazon.com/Foundations-Statistical-Natural-Langua...

[2] http://www.amazon.com/Speech-Language-Processing-Introductio...

Here is a review [0] by Bob Carpenter of Foundations of Statistical Natural Language Processing [1].

[0] http://www.amazon.com/review/R2FUAZHGUOERHV

[1] http://www.amazon.com/Foundations-Statistical-Natural-Langua...

NLP:

http://www.amazon.com/Foundations-Statistical-Natural-Langua...

http://www.cs.colorado.edu/~martin/slp2.html

(and the python NLTK book is not bad)