Installing additional LaTeX packages is optional for most situations.
already included in teTeX-2.0.2
only needed if you want line numbers, needs
installation and adding to preamble ()
or specifying lineno as moreopts in class.
only needed for long table support
only needed if you need arbitrary placement of text and graphics (needs install)
Required by textpos (already included in teTeX-2.0.2)
Control list spacing (optional)
Special formatting of program listings (think code tag)
Usually you install additional LaTeX packages (you can download them from ctan.org) as follows
cd /apps/teTeX/2.0.2/share/texmf/tex/latex tar xvzf /t/textpos.tar.gz
The package directory should appear as immediate subdirectory of the share/texmf/tex/latex directory.
mv tex-archive/macros/latex/contrib/textpos .
Sometimes you need to run installation script (see README, if any)
cd textpos latex textpos.ins
Finally rebuild ls-R so that LaTeX will find the new packages:
cd /apps/teTeX/2.0.2/share/texmf ../../bin/i686-pc-linux-gnu/texhash ls -alF /apps/teTeX/2.0.2/share/texmf/ls-R # double check