To do so, you must first connect to your ISP (Internet Service Provider, e.g.verizon)
The preferred connection method is SSH (Secure Shell) . Secure shell does not transmit your password in the clear across the internet, as telnet and ftp do. Also, SSH provides a gui interface for file transfer (sftp - secure file transfer protocol) which is much more convenient than the standard ftp.
If you are running Linux, Unix, or a Mac, ssh is probably available on your system.Source code is also available at http:/openssh.org.
Once you open ssh, you set up a connection with any one of the Unix
machines that are available for remote login. The following is a partial list.
Each machine's name is atriumX.its.brooklyn.cuny.edu, where the X may
be replaced with any one number from the following list:
2-9, 11, 12, 31-39, 42-46, 63, 90-95, 99
Putty can be used as a telnet client, and also has free windows install packages at: http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html
If you want to use telnet, and ftp, you may see these instructions.
All of this information comes from the ITS services site.