Hi Skittle,
MTS uses a Windows explorer style interface. It most commonly comes as part of the Windows NT option pack. You can check if it is installed by: Start menu->Programs->Administrator tools(I think!)->Windows NT options pack->MTS Explorer. I believe that it also comes as part of IIS.
I think that it comes with some IIS packages already installed so check these out to get an idea of what is happening.
Generally, MTS should be run on a server. A COM dll can be dragged and dropped into a new package that you have set up. Each interface exposed by your COM dll will then be shown as a separate component within the package.
You can then set the security and transaction properties for your package or individual components if required.
HTH, Andy