Downloading to computer and then uploading unzipped files by ftp is time consuming on ADSL internet.
Get download link from http://www.joomla.org/download.html .
Assuming installing for an account camcomm:
cd /home/camcomm
مجلد مشترك HTTP://joomlacode.org/gf/download/frsrelease/16024/69674/Joomla_1.7.3-Stable-Full_Package.zip
unzip Joomla_1.7* -d public_html
chown -R camcomm:camcomm public_html/*
Then open website and follow installation procedure.