To learn how to connect to SSH you should read the tutorial below first:
http://www.unitedsupport.co.uk/helpdesk/index.php?_m=knowledgebase&_a=viewarticle&kbarticleid=25&nav=0
Basic SSH Commands
ls -al <directory> # List directory
cd <directory> # Changing directory
pwd # Current path
mv <file to move> <directory to move to> # Moving files
cp <file to move> <directory to move to> # Copying files
passwd # Change password
telnet <hostname> # Command line telnet
ftp <hostname> # Command line ftp
ssh <hostname> # Command line ssh (secure shell)
exit # Returning to previous shell
Changing File Permissions (CHMOD)
You can change a file's permissions with the Linux command chmod. For example:
chmod -R 755 <filename>
will give the folder 'directory' and all its contents 755 permissions.
For more help with chmod you can type the following into SSH:
chmod --help
GZIP Compression
Gzip allows you to upload or download your entire site in the form of a compressed .tar.gz file.
If you wanted to compress your entire sites html folder into a single file to download you can use the following commands:
cd /var/www/
tar -czf html.tar.gz html
Now your entire html folder will be placed into an archive called html.tar.gz in your /var/www/ folder, so you can FTP in and download that file.
If you create a tar.gz file on your computer and upload it, you can then uncompress and extract that file to your webspace using the following command:
tar -zxvf html.tar.gz
In Summary
There is so much more you can do with SSH, and it can be a real time saver, editing files 'live' on your web hosting account. You can always Google to read more and find lots more handy commands for using with your SSH access.