After taking the Tour of Go, I bought Go in Action and haven’t regretted it. It’s great for someone who already knows how to program, but wants to get up to speed on the details and inner workings of Go. The authors, William Kennedy, Brian Ketelsen, and Erik St. Martin, did a great job of giving examples I could expand into a practical applications while keeping them concise (which keep the book light, in both reading and weight). This is definitely a must read for anyone who wants to move beyond the syntax of Go and ramp up on its idioms.