The style sheet document provides guidelines for designing the different elements of a magazine cover, including the masthead, main heading, cover lines, and additional information. The masthead uses bright red to attract attention and symbolize strength. The main heading and cover lines are designed to match the main image in font and color for consistency and clarity. The cover lines are underlined and in a bold sans-serif font to point out extra content. Additional information uses specific colors like black, white, or red to stand out from the background.