I started off with The Little Go Book, which gives a nice high level overview, touching most important things of the language. It's really short (which meant I had to reread some things a couple of times), but gives you a direct feel of the language and you'll find out if you like it or not almost immediately.
Then I bought "The Go Programming Language" and "Go in Action". I found the latter to be the best of the 2. Even though people praised "The Go Programming Language" all over the Internet, I found it a bit too academic for my tastes. The latter is much more practical. YMMV.
I get my Go news fix from golangweekly, which helps in keeping up with the language and learning what's out there and how other people use Go.
Off course, the best way to learn a language is always to start using it. So I started writing out our company CLI tooling with Go (which used to be in Ruby, so now speed improvements ++ and less compatibility/support issues).
Some weeks ago I also bought Web Development with Go. Haven't started it, but heard a lot of good stuff on the screencasts and want to learn more about web (and actually server) development with Go.
Hope this helps.