Gass, S. & Selinker, L. (2001). Second Language Acquisition : An Introductory Course. Mahwah, NJ. Lawrence Erlbaum Associates.
The book provides a good introduction to the second
language acquisition field, as well as the research done in the area.
It covers all the major issues, such as first language influence,
universal grammar, interlanguage in context, and classroom second
language learning. The discussion questions at the end of each chapter
are particularly useful for students in an SLA introductory class.