You will need a ssh 'client' (software) on your PC. Putty is a very good and common program for Windows and Linux (Mac even?) - google it.
You will need to know the IP (Internet protocol) address of you N800. Get this by running xterm (while your connected to the same network your PC is on, of course) and typing "/sbin/ifconfig[Enter]" at the ..$ prompt, and look for "inet addr: xxx.xxx.xxx.xxx". You will have entere this address into Putty for "Hostname (or IP address)" and click [Connect]. That should get you a window with a login prompt. Login as user "root" and passwd "rootme".
Now you have a xterm-like session running on your PC but 'served' from the N800. This is known as system-level or command line interface (CLI). You'll need to learn some Unix commands to do anything useful.
Now sure how it will help you with your Thai needs, but that's how ssh sessions are done.

EDIT: BTW the inet addr you want is the one listed after "wlan0" not 127.0.0.1 - that is an address that always represents the machine itself (known as localhost).