Here are the simple steps to install nodejs on a linux machine. I always struggle to get the latest version from http://nodejs.org, and wanted to write up the simple steps to get installed:

Manually

$ wget http://nodejs.org/dist/v4.2.2/node-v4.2.2-linux-x64.tar.gz
$ tar xzf node-v4.2.2-linux-x64.tar.gz
$ sudo cp -rp node-v4.2.2-linux-x64 /usr/local/
$ sudo ln -s /usr/local/node-v4.2.2-linux-x64 /usr/local/node

Note: This is referencing version 4.2.2, but update the commands with the version you are wanting to install.

Package Manager

https://nodejs.org/en/download/package-manager/#debian-and-ubuntu-based-linux-distributions