For the stable versions, the official Node.js website supplies linked binaries that provide the easiest way to install Node.js on Linux, Mac OS X, and Windows. Note that you need to download the right architecture version for your operating system. If you use Windows or Linux, make sure to download either the 32-bit or 64-bit version according to your system architecture. Mac users are safe to download the 64-bit version.
The Node.js version scheme works in a way similar to that of MongoDB, where even version numbers mark stable releases, and so versions 0.8.x and 0.10.x are stable, while 0.9.x and 0.11.x are unstable releases and should not be used in production. The latest stable version of Node.js is 0.10.x.