Templates are an important function in Indesign. They're useful in many different aspects of design - they help you stay on track when you have to make the same kinds of documents often. When I worked as a corporate designer, we had a template for each kind of brochure: whitepapers, flyers, and multiple page documents. It helped ensure that each brochure perfectly matched the brand + each other with no effort (once the initial templates were done).
40 Things You Can Create For Your Business With InDesign
40 things you can create for your business with Adobe InDesign
25 Unique Adobe InDesign Tutorials for Newbies - DesignM.ag