Listing all values of taxonomies

I'm just trying to list all entries of a passed in taxonomy for a collection of pages. I have a collection of sermon pages and they have an author and book associated:

title: 'The Title of the Post'
taxonomy:
    category: 'sermon'
    author: 'Person A'
    book: [Matthew,Mark,Luke]

and

title: 'Another Title of a Post'
taxonomy:
    category: 'sermon'
    author: 'Person B'
    book: [Mark,Luke,John]

What I want to see is the following:

List of Authors:

• Person A
• Person B

List of Books

• Matthew
• Mark
• Luke
• John

How do I output this list? And where can I learn more about the properties of the taxonomy object besides examples that list tags of a given page/item? Thanks.

This is SUPER HELPFUL, thank you!

This method produces a collection that I can now filter and sort. I also was able to do a count of the matched entries like so using findTaxonomy():

taxonomy.findTaxonomy({'book':[PASSED IN TAG VALUE]})

Thanks again!