Not sure if Tri Def is compatible with Mitsubishi 3D Ready TV's - the Tri Def website says they are only compatible with Samsung? http://www.tridef.com/support/faq/category-14.html
Anyhow, let's assume it is compatible for the moment and works in a similar way as nVidia GeForce 3D vision. Connect your computer graphics card via a DVI to HDMI or HDMI to HDMI cable to one of your TV's HDMI in sockets. Your TV will recognize the new device and ask you to give it a name - choose PC.
(I am assuming you have a DVD drive installed in your computer and DirectX 9c, otherwsie things are going to get a bit more complicated.) You may have to adjust your video card settings on your PC to ensure they are at 60hz refresh rate and to 1080 resolution.
You may also have to download a DVD decoder: http://www.tridef.com/support/dvd-decoders.html
You will need a pair of stereoscopic active shutter glasses to plug into your TV. If they came with an emitter, plug the emitter into the TV's 3D glasses emitter socket and then the glasses into the emitter.
Set your TV to 3D mode. Off you go. That's the basics anyway!