First half of this answer (quoted parts) is taken from TorifyHOWTO Wiki page, updated by me to be more current, and I have reconstructed images that have broken links there according to their description in the how-to. No copyright infringement intended.
Putty is a free application suite for Windows that provides such tools
as Telnet, SSH and SCP, along with a very good xterm emulator. It's
written and maintained by Tatham and can be downloaded via links on
its homepage at http://www.chiark.greenend.org.uk/~sgtatham/putty/.
The first application to Torify is Putty itself. This is a combined
Telnet/SSH client. When started, you are presented with a Session
configuration screen (shown below).
This screen is used to select the host you wish to connect with, the
preferred port and the connection type, (
also enables a session configuration to be saved and retrieved. For
this reason, I suggest configuring the other session tabs first and
then returning to this one in order to save the configuration.
Only one other tab requires configuration specifically for Tor, and
that's the Proxy tab (shown below).
The above image shows the settings exactly as they should be set for
usage with Tor. Pay particular attention to the "Do DNS lookup at
proxy end:" option. If this is set to Off or Auto, then DNS will leak
information about what services are being used.
That's it for Putty. Return to the Session tab and save the
configuration if desired.
For PuTTY command line tools, please refer to the source how-to Wiki.
As for port-forwarding, there is nothing in particular that you'd need to set up for that on your router, since your proxy will be the local Tor's Vidalia listening on
localhost port you configure and it will be forwarding requests through the TCP connection using standard HTTP ports. Make sure you have Vidalia properly configured, running and connected to Tor network, and especially pay attention to Vidalia's local port that should match the one used in your PuTTY proxy configuration. This setting can be found in
Settings -> Advanced -> Tor Control in the Vidalia Control Panel (see images below).