If you want to see Chinese characters when using telnet or ssh, you will need to download a client that supports UTF-8 encoding. PuTTY supports it, but remember to set the character set transalation to UTF-8 (e.g. Window, Translation, change Character Set Transalation to UTF-8).
As for using wl-500gP with 1.9.2.7-10 firmware and Samba (windows file sharing), to support Chinese character, you will need to install Samba3. In your Samba3 smb.conf, add the following two lines to the [global] section:
unix charset = UTF-8
display charset = UTF-8
Firmware 1.9.2.7-10 only comes with samba2. Samba 3 isn't easy to install and configure (though it is worthwhile running it instead of samba2, it seems to run faster and the UTF-8 support is a plus). There are some good tutorials on it, but most of the tutorials are older versions of samba3. Some of the steps/workarounds are no longer needed.