I typically only do drums with MIDI since I'm not a drummer, but let me tell you, if there was a magic utility to convert WAV to MIDI, life would be so much easier! My drum programming consists for several days of listening closely to the drum pattern, accents, etc. and then as closely as possible recreating them beat by beat using a MIDI editor (I used to use Cakewalk SONAR, but now use Steinberg Cubase SX
Basically, in a sequencer such as Cubase, you have a time grid set to a certain tempo. Visually on the grid you can see the different beats; 1 & 2 & 3 & 4 &, as well as any fraction in between. A simple drum beat would be kick drum on beats 1 and 3, and snare drum on 2 and 4, while a constant but dynamic sequence of hi-hat is played on every beat. You manually place notes at these postiions to create your pattern. Then you either repeat it for any number of measures, or create a new pattern for other sections of the song, varying each ever so slightly to avoid the track sounding too steril and fake. It can be quite maddening and it really takes a lot of effort and dedication to get something sounding halfway decent. But once you get good at it, it becomes easier.
The same goes for any other type of instrument. Music is mathematics, and you have to look at it from that point of view to do MIDI programming.
Now of course you could just bang out the drums on your keyboard and perform the songs live, thus eliminating the manual programming aspect. I do this for keyboards, since I can actually play that instrument, but drums are a different story. I think not only my fiance but the rest of the apartment complex would kill me if I brought live drums into my little studio room and tried to learn how to play them. [img]images/smilies/smile.gif[/img]
I know this is probably way more information than you were looking for, but I could go on for days. I've contemplated doing a tutorial on how to do MIDI drum programming from scratch, much like POD GOD's tutorials on turning already composed MIDI into nicer sounding backing tracks. Some day...