I have previously written this article on how to install the latest LibreOffice on your Debian based Linux System.

In this article I will show you and easier method for installing LibreOffice 4 on Ubuntu 12.04Â Precise Pangolin, Ubuntu 12.10 Quantal Quetzal and Ubuntu 13.04 Raring Ringtail.
LibreOffice 4 was released in February 2013, but we had to wait for the official Ubuntu packages from The Document Foundation’s PPA.
Follow this three steps for a succesfull installation:
1. Add the LibreOffice repo:
$ sudo add-apt-repository ppa:libreoffice/ppa
2. Update the system:
$ sudo apt-get update
3. Update your LibreOffice version to 4.0:
$ sudo apt-get dist-upgrade