golang.org offers two types of downloads for Linux: a source tarball and a pre-compiled tarball. If you download the pre-compiled tarball, you just have to extract it somewhere and set some environment variables (all explained in detail on golang.org).
If you really want to install Go via your package manager, you can install the golang package from the Ubuntu repositories. However, this package is naturally on an outdated version of Go. Also worth mentioning is godeb[1] which can generate and install a .deb of any version of Go for you.
To install simply download the tarball, extract it to /usr/local/ and add /usr/local/go/bin to your $PATH. If you want to install it to a different location (I like to keep it in my home directory), you just to set $GOROOT to that path and set your $PATH accordingly. To update, just remove the old go dir and extract the new tarball in the same place. I'm ok with it.
Simply is never that simply. There is always something that happen to suck in IT. You think you have done everything right and sometime, you just made a little misinterpretation that screw everything and you can lose a lot of time figuring out what.
That being said, I had no problem installing go on my ubuntu, despite the fact that I consider that the installation process sucks.
That's it, it is that simple. All you have to do now is set your $GOPATH, and you would need to do that even if you had installed Go through a package.
One would hope that being six to ten months behind the development branch wouldn't make very much difference. If it does, I'd argue Go isn't mature enough for general use yet.
The Go project makes stable releases every 6 months. They are extensively tested and fully compatible with all previous major releases. But we do introduce new tools, libraries, and minor language features. Developers almost always want to be using the latest stable release of Go. (There's seldom a reason not to.)
It's not behind the development branch, it's behind the stable branch. The stable branch is called stable for a reason, because it's stable. You can still use the older versions and they're not bad, but the newer versions have brought improvements, and I see no reason why Ubuntu shouldn't package new stable versions when the Go team is committed to stability.
If you really want to install Go via your package manager, you can install the golang package from the Ubuntu repositories. However, this package is naturally on an outdated version of Go. Also worth mentioning is godeb[1] which can generate and install a .deb of any version of Go for you.
[1]: http://blog.labix.org/2013/06/15/in-flight-deb-packages-of-g...