If you have the time, I would start by taking Andrew Ng's machine learning class and then this NLP class when it is next offered in September 2016 https://www.coursera.org/learn/nlp
Ah yes, the one I've heard about but still have to take. :) Well, I guess I should give Coursesa a chance. (Somehow I'm not fond of their "timelined" format, it seems redundant if you're communicating with a machine. I hope the future of online learning will avoid it like the plague.)