There are two new books for Finale and Sibelius users. The books are specifically written for Sibelius 7 and Finale 2012. If you are looking for some guidance, then these texts may be a help to you. Check out the Amazon Links to see what others are saying about the texts.
The text Sibelius: A Comprehensize Guide to Music Notation, Second Edition I co-authored with Vince Leonard, is in its second edition and is best for Sibelius 6 users. You can read more about it in my 2011 blog post when the new edition came out in 2011. Amazon usually has the most discounted price.
If you are a Sibelius 7 user, I recommend Sibelius 7 Music Notation Essentialsby James Humberstone. The book is well organized and also includes links to Media so you can check out videos and demos done by the author. Check out the information and reviews on Amazon. In my online Berkleemusic course, Music Notation Using Sibelius, I recommend this book for Sibelius 7 users.
The Third Edition of Finale: An Easy Guide to Music Notation that I co-authored with Vince Leonard is now available. It was edited by Jonathan Feist, who is the author and instructor for the Berkleemusic course: Music Notation Using Finale. The text has been revised and updated to include the new features introduced in Finale through version 2012. There is a companion website where you can check out one of the chapters of the book and other files to make using the book more efficient www.finalebook.com. Check out the reviews and other information on Amazon.