Prety simple, you need an interface like the one you are talking about. Then you need a program like garage band, cubase, pro tools, whatever, tha has a drum program in it that will capture the midi and then trigger sounds.
The thing that confuses most people is that MIDI is NOT sounds, it is a control language that will tell a program what ro play, when, how loud, for how long etc...
You can also record the audio from your edrums as well.
Check this out
i hope this helps you get started