I don't know a lot about MIDI to be honest. I know that MIDI can be made to sound a lot better than robot-music but I have never been able to work my own magic to do it. I think Kevin (Taylor) does that kind of stuff..

What I do, to create a backing track, is use a program called Reaper to record my rhythm guitar and bass. And then I use a VST plugin for the drums. The drum plugin is called EZDrummer, which is basically the realistic sounding instruments coupled with pre-fabricated grooves in MIDI format. The grooves are categorised and easily previewed to get the feel I want, then I simply drag-and-drop them into Reaper's time-line.

I can either render the track at this point and use it independently of the Reaper recording software, or I can use the Reaper software to play over the top of in its raw form. Since I use VST plugins for my guitar fx as well, I usually just play it within the Reaper environment.

Reaper is free, the plugins are not... but they're not that expensive either. I'm fairly sure EZDrummer has demo plugins you can download to see if they are right for you as well.