Just because some people had missed the Sibelius blog and might have missed this too:

http://sibelius.acrobat.com/p81445367/

Sibelius's senior product manager gives a pretty in-depth tutorial about the ins and outs of page layout.  If you find yourself doing a lot of manual dragging in your scores you should definitely check this out.  So much better when you get most of that stuff automated from the start.