Adobe InDesign is a production artist's best friend (you can't do everything in Photoshop) because it allows you create blueprints for a huge range of projects like flyers, brochures, magazines, newspapers, posters, business cards, postcards, stickers, comics whether you're going to print or designing online. If you love Adobe Illustrator (and frankly, who doesn't?), you'll be impressed with the power of InDesign.