Read this thread:
http://www.guitarforum.co.za/recordings/drum-program-required-whats-best/ - starts out with software preferences, but later in the thread there is some discussion about programming realistically.
Manfred Klose wrote:
the easiest way might be when you are done programming the drums, highlight all the midi notes and selected the "Huminze" function
+1. Software with a Humanize function takes a lot of the hard work out of programming drums. Otherwise you have to sit there for days, and play around with velocity and timing variations on every single note in the drum parts - and you still might not get it to groove.