Getting Started in Natural Language Processing
As a linguist and software engineer I can't imagine someone doing serious NLP without ever having studied [concrete] syntax trees and such. It is easy to impress people with some tokenization but it's n-grams that are really useful in the real world, as is understanding syntax trees and all the interconnections possible inside them so you can NLP the shit out of real world text/speech, instead of simple examples with a tagger (and a good, carefully crafted for a demo like Apple's, trained set of tagged data). This is a good summary article with very good links nonetheless.