This is something I have always struggled with, but a friend of mine (Les Edgerton, author of Hooked) sent me a link on how he does it.
http://lesedgertononwriting.blogspot.com/2010/04/outlining.html

I think it is cool for a first pass and incorporates a lot of elements of a good outline, like wiggle room for characters to express themselves. I have another method I will link as soon as I find one that is better to add in subplots, etc.