Simple to learn

Even if the language is pretty recent, there are many resources to learn Go. The first one I stumbled upon was Tour of Go, it allows to discover the Go features and test them online. You can even run the web server locally if you want to learn Go while traveling, it has even been translated in many languages. In a word, awesome!

I also tried the Go Koans, but the tests are less detailed and progressive than Ruby Koans. It took me an evening to complete these exercises.

There are several free e-books to get started with Go:

Go is mostly simple to grasp because there are few concepts. The Go Lang spec is less 100 pages long.