I would strongly recommend purchase of the following book:

BOOK INFORMATION:

Infinite Words: Automata, Semigroups, Logic and Games
By Dominique Perrin & Jean-Éric Pin
Volume 141 of the Pure and Applied Mathematics series
Hardbound, 550 Pages
Published: FEB-2004
ISBN 10: 0-12-532111-2
ISBN 13: 978-0-12-532111-2
Imprint: ACADEMIC PRESS

http://www.elsevierdirect.com/product.jsp?isbn=9780125321112

JUSTIFICATION:

I strongly recommend purchase of this book because it is the only source out there that contains all the major results of the field thoroughly gathered in a single place, making it easy for someone new to the field to get up to speed on what is known without wading through tons of papers. Furthermore, the information contained in the book is very well presented and organized, so even if it were not the only book in its class it would be worth adding to the collection because of how well it treats the subject.

It is worth noting that I am writing this recommendation not as a specialist in the field of automata myself but actually as a quantum physicist, which demonstrates that this information is useful not only for narrow specialists within the field of formal language theory but for other diverse disciplines as well.