First I am relatively new to linux particularly Ubuntu 14.04 so if you intend to help me, just indicate the exact commands i need to type to get QGIS 2.6.1 Installed

I have tried to follow the instructions provided here https://www.qgis.org/en/site/forusers/alldownloads.html but I haven't managed to install anything.

Can someone explain to me step by step process of doing it. Right from adding the QGIS repository on the sources list.

I have Ubuntu 14.04.1 LTS installed on a 32-bit Dell Latitude E4310 Machine