Peter Barry, Beginning Theory: An Introduction to Literary and Cultural Theory, Beginnings, 3rd edn. (Manchester: Manchester University Press, 2009).
I bought this yesterday having previously bought the first edition in 1995 and the second edition in 2002. I think it ranks as one of the best introductory overviews of critical theory available.
It covers the usual suspects of liberal humanism, structuralism, poststructuralism, postmodernism, psychoanalytic criticism, feminist criticism, lesbian/gay criticism, marxist criticism, new historicism, etc., and does so lucidly with examples of how the approaches work in practice, as well as places to ‘stop and think’ to check one’s understanding along the way.
The second edition added a chapter on ecocriticism, acknowledging the burgeoning interest in ‘green’ approaches to literature, and added a chapter (an excellent brief treatment, in my opinion) on narratology as a branch of structuralist theory.
This third edition is also expanded rather than revised, and now includes a chapter outlining the story of recent literary theory in ten significant episodes, from the Indiana University Conference on Style in 1958 to the Sokal Affair in 1996. A second additional chapter provides a summary of some new ‘isms’ which have appeared since 2000 or so, not least at a time when a number of significant voices have been declaring that we now find ourselves in an ‘after theory’ period.