Introducing Sociolinguistics

There are a number of sociolinguistics/language in society textbooks out there, but they are either too simple or not comprehensive enough or formatting in such a way to make them hard to read. Introducing Sociolinguistics by Mesthrie et al. fits the bill better than any other books I've seen or used for advanced undergraduate or beginning sociolinguistic courses. I like it because it covers an impressively wide range of topics and because it has an open format, with lots of maps and/or diagrams that make the text easy to follow. But it isn't just a a picture book. The book treats its subject in sufficient depth for the levels of students I've cited. I've just started to use it as a textbook myself.