In Clash! Markus and Conner, spin through a range of cultural differences covering geography, gender, ethnicity, class, religion and workplace. The book is a great overview of the different ways in which our multiple identities influence our behaviour and lives, covering a wide range of issues and a broad overview of the challenges of living in the modern world.
The book has a US focus (there is a whole chapter devoted to the differences between regions of the USA) and although the authors acknowledge the dominance of WEIRD (Western, Industrialised, Educated, Rich, Democratic) cultures in shaping academic thinking about cultural differences, at the same time they fall prey to this bias in their examples.
Their overall take is that the balance between independence and interdependence is perhaps the most critical in managing our interactions with other people. This is a good introduction to many of the themes of cultural difference, but other books dive deeper into some of the details and practical solutions.