The transition from sequential to parallel computation is an area of critical concern in today's computer technology, particularly in architecture, programming languages, systems, and artificial intelligence. This book addresses central issues in concurrency, and by producing both a syntactic definition and a denotational model of Hewitt's actor paradigm—a model of computation specifically aimed at constructing and analyzing distributed large-scale parallel systems—it substantially advances the understanding of parallel computation.
Introduction. General Design Decisions. Computation in ACTOR Systems. A More Expressive Language. A Model for ACTOR Systems. Concurrency Issues. Abstraction and Compositionality. Conclusions.
This is another of those books I've never quite finished (for various reasons -- some of which are that it gets me off on too many tangents from all the fantastic ideas). That said, I feel confident recommending this as the best actor model book out there right now. Some of it might seem dated, but it gives you a great overview of what actors are, how the computational model works, and how you might start to think about building systems on top of them.