Picture taking won't be much of a transition at all. In fact you probably already know more about photography than the majority of dSLR owners. The learning curve will be with post processing and some miscellaneous camera features that you may not be familiar with.
How good are you with computers? I highly recommend getting a copy of Lightroom or Aperture (Apple users). It'll be a little tricky at first, but it's worth learning.
As far as the camera, it'll have a whole bunch of completely useless settings (if you're coming from film). I'd shoot in full manual, Av, and Tv. You should have enough photography knowledge to not use the fancy settings they put for people who don't know how to use a camera.
Welcome to digital, don't hesitate to take a lot of shots, memory is cheap!
