Good introductory book for Markov processes
Solution 1:
Theory of Markov Processes by Eugene Dynkin is a paperback published by Dover, so it has the advantage of being inexpensive. The author has made many contributions to the subject. Dynkin's lemma, the Dynkin diagram and the Dynkin system are named after him.
Solution 2:
"An Introduction to Stochastic Modeling" by Karlin and Taylor is a very good introduction to Stochastic processes in general. Bulk of the book is dedicated to Markov Chain. This book is more of applied Markov Chains than Theoretical development of Markov Chains. This book is one of my favorites especially when it comes to applied Stochastics.
Solution 3:
An Introduction to Markov Chain Analysis and An Introduction to Markov Processes would be a good start.