SSH allows you to connect to linux machines over the network. You'l will need to have a SSH server running on the linux server hosting the database and then have a ssh client on your machine. You get SSH clients for linux and windows (PuTTY).
Note that SSH is console based so you would have to learn the console commands to control postgres. the common command is psql but you would have to read the manual for more details. You can find more help about SHH and postgres admin at http://www.linuxforum.com/forums/
You could get a frontend which can connect to the server for you. I use phppgadmin which is web-based so I can use it from windows or linux. You'll need phph anda web-server running though.
You could try fontend applications (normal programs). Theres the free pgadminIII at the postgres site and the very professional pgmanager by ems. Use google to find more. Or visit linuxforum.com