Is there a way to animate display:none to display:block using CSS so that the hidden div slides down instead of abruptly appearing, or should I go about this a different way
What about
$("#yourdiv").animate({height: 'toggle'});
$("#yourdiv").animate({height: 'toggle'})
Toggle will switch your div on/off, and the animate should make it appear from below. In this scenario, you don't need the specific CSS to "hide" it.