Recording electronic drums

I'm using Studio 8.5 and, for the first time, have been asked to record drum tracks with a Roland electronic kit. What do I need to know? Help!

What Cactus said. Record the MIDI output, not the audio.
 
Later, you can use the drum kit's own sound module to render to audio if you like, but chances are you have better drum samples on disk and may elect to substitute some or all of the drum sounds with other sources. 
 
The audio output from the drums' own "brain" (why do they call the sound module a "brain"? Isn't the drummer the brain?) is going to be stereo, so you'd be stuck with whatever mix the drummer made. If the bass drum needs to be louder, or the hi-hats are too loud, or the toms are panned too wide, there'll be nothing you can do about it.
 
From the mixer's perspective, recording electronic drums is wonderful! No microphones, no acoustics, no phase problems, no bleed, no squeaky pedals, just easy editing and mixing.

There's always latency.. it might be so little as to not be noticed by most people. They say we can notice anything more than 5 ms. And if your recording the midi it doesn't really matter as it will get quantazied anyhow. 

Thanks very much for all of those responses.
The project is to produce a 4 song demo putting down the drum tracks first then layering the other instruments and vox in time honoured tradition. Playing live the drummer gets a great sound from his Roland kit which I'd be happy to record. How would latency be a problem if the other instruments are synching their playing to the original drum track?