Your best bet is to go find a textbook on physical methods in inorganic chemistry.
Having said that, there is a very brief introduction to this very topic here by Andrew Barron (Rice University). If you need dramatically more information - including on the technique itself - refer to the first sentence of this post. It really helps to have spectral data in front of you to look at, scribble on, and annotate to begin the learning process, I found.