Reading 23: HMM Overview

Paper
Rabiner, Lawrence R. "A tutorial on hidden Markov models and selected applications in speech recognition." Proceedings of the IEEE 77.2 (1989): 257-286.
Direct Link: http://www.robots.ox.ac.uk:5000/~vgg/rg/papers/hmm.pdf

Notes
This paper is very long, but it also goes into a lot of detail.  For the class, if you can just look over the primary overview in the first few pages, you'll be fine.