ssh is a secure version of the standard rsh. When connecting to machines, you should always use ssh. Instead of using telnet, rsh, rlogin, rcp, use their secure analogs, ssh, slogin, scp.
There are numerous advantages, but the biggest one is that ssh encrypts the connection that it creates, so anyone on the network sniffing for passwords won't see yours in plain text like they would if you were using telnet. ssh also verifies that you're connecting to the machine that you think you are.
Free versions of ssh are available for you to install and use from home. See
http://www.openssh.org
A simple ssh client freely available for Windows systems is putty:
http://www.chiark.greenend.org.uk/ sgtatham/putty/
See also the man page for ssh/