Becoming Fluent

A genuinely fascinating overview of the cognitive science principles that one might exploit (or find troublesome) in the course of learning a language as an adult. Some of the principles are applicable to acquisition of any skill, not just language. While the book provides some actionable suggestions for studying, I would not recommend it if you're looking for a concrete study plan. This text places the onus is mostly on the reader to apply the concepts to their own learning.