Books
- Mark Lutz: Learning Python (standard book, introduction, reference)
- Michael Dawson: Python Programming for the Absolute Beginner
- Michael Dawson: More Python Programming for the Absolute Beginner (haven't read this one yet)
- Bird et al.: Natural Language Processing with Python
Online Tutorials
- Python 3 Course by Bernd Klein
- NLTK Book online (also contains a general introduction to Python programming)