I've been on a huge linguistics kick the last few weeks, so my recent reading reflects that.
Just finished reading "The Language Instinct: How the Mind Creates Language", by Steven Pinker. It's by far the best introduction to linguistics for the lay public ever written. Each chapter covers a different major field or topic in linguistics, with an overall unifying theme being an examination and promotion of Chomskyan grammar theory and the notion that language is an innate human instinct controlled by modules in the brain made possible by natural selection. It's several semesters worth of introductory and intermediate college linguistics classes packed into one book.
Before that, I read "Language Myths", edited by Laurie Bauer and Peter Trudgill. The book is a collection of 21 essays written by 22 linguists laying waste to the most common language myths held by the general public and non-linguist academics alike. It's a great introduction to language in general and does a wonderful job setting the record straight for so much of the nonsense behind myths that lots of people consider facts or common sense about language that, in fact, turn out to be gravely mistaken.
After that, I read "Word on the Street: Debunking the Myth of a 'Pure' Standard English", by John McWhorter. This book is probably the most erudite and devastating slam on the false attitudes behind prescriptivism and sociolinguistic prestige I have ever read. It thoroughly dismantles prescriptive grammar attitudes, embarrasses those who cling to prestige notions of language and dialect, and sheds much needed light on language discrimination and linguistic misinformation in the United States. Beyond that, it's a fascinating overview of creole languages, issues with translation, recommendations for English language education, and a really intriguing examination of African American Vernacular English - its grammar and evolutionary history.
Now I'm reading "English with An Accent: Language, Ideology, and Discrimination in the United States", by Rosina Lippi-Green. I'm not very far into the book, but so far I really like it and it's extremely well researched. The book is evidently one of the most comprehensive sociolinguistic examinations of the attitudes behind and consequences of language discrimination.