Reindex Magento Data via SSH

Manual: http://kb.siteground.com/reindex_magento/
How to enable SSH/Shell Access in cPanel: http://www.siteground.com/tutorials/ssh/ssh_cpanel.htm
How to Use Putty to Connect to SSH: http://www.siteground.com/tutorials/ssh/putty.htm
Putty: http://www.chiark.greenend.org.uk/~sgtatham/putty/