How to add LaTex packages in Ubuntu

If the package in the sty format:

1. create a new directory under tex tree

–> sudo mkdir /usr/share/texmf-texlive/tex/latex/

2. copy the package inside the new directory

3, run the following command

–> sudo mktexlsr


Source: http://ivanky.wordpress.com/2010/02/05/installinglatexpackages/