Can you suggest a source (book, lecture notes, etc) that provides a good introduction to mixture modeling? I would like something that discusses (mixes?) theory and application at the graduate level. If it offers examples from the social sciences, even better.
For finite mixture models, I would recommend McLachlan and Peel's Finite Mixture Models, though it might be a bit dated and not particularly social sciencey.
For a quick intro to get the basic idea and play around in Stata, take a look at Partha Deb's slides and
fmm from SSC. Lots of economics examples here, but the halibut length with unobserved gender is a timeless classic.