How to SSH from windows
What is SSH?
SSH is a secure shell protocol, it allows login to a remote machine over an encryted connection. Most unix vendors supply ssh client and server software with their distributions. If you need to be secure then you need to find out more for yourself ;D.
The first two programs listed will allow you to more securely transfer files between windows and a system running the ssh server (typically available on unix systems) and also to execture a remote shell. These may also be possible to achieve using the cygwyn package or in other ways (you can find out if you need to I'm sure).
Cygwin
Cygwin is a large collection of GNU and Open Source software which provides a UNIX like (POSIX API functionality) environment on windows.
Installation of Cygwin allows many useful tools to be run on windows, a terminal with unix commands such as ssh can be installed with which to log in to remote machines, X11 can be installed on your windows machine so that graphical programs can be run remotely if needed.
Secure file transfer program: WinSCP
WinSCP allows you to connect to a machine (which is running the appropriate ssh server program) using the sftp (secure file transfer protocol) to transfer/manage files with file manager or explorer like interface.
WinSCP is an open source project, it can be downloaded from the WinSCP website
Secure Shell Program: Putty
Available from here: http://www.chiark.greenend.org.uk/~sgtatham/putty/
Allows xterm emulation, telnet/ssh client for w32 (windows).
Commercial ssh client from ssh.com
ssh.com provides commercial software using the ssh protocol, I used to recommend this software because a version was available free for non-commercial use.
Get so ssh.com and download the version of ssh from there http://ssh.com/
It might still be possible to get a version which is for non-commercial use which is free for academic use. The location of this download has moved, or it may be no longer available.
To install on windows download and run the install program, the last one I used was SSHSecureShellClient-3.2.9.exe
For commercial use you can either pay (cost in 2004 was 109 Euros) or Download evaluation version which will last for 45 days: Register for client/server evaluation
Commercial enchanced X11 terminal MobaXterm
Mobatex.net provide a home (freeware) and professional version of their MobaXterm software which provides ssh login and file transfer between windows and unix system running ssh.
Alternative software: srcf
Student run computing facility at University of Cambridge has more information here: http://www.srcf.ucam.org/utilities/ssh/