OwnCloud provides ready-to-deploy packages for popular Linux distributions such as Debian, Ubuntu, Fedora, RedHat Enterprise Linux, CentOS and openSUSE. Refer to http://software.opensuse.org/download/package?project=isv:ownCloud:community&package=owncloud to get the right repo info.
Below the quick install for Ubuntu server 14.04.

Install the Owncloud repository for Ubuntu 14.04 on your system:

Add the repository key to apt

Then just update and install: