Microsoft Publisher is a desktop publishing program that allows users to create a variety of publications like greeting cards, flyers, posters, newsletters, and brochures. It offers quick publication templates, clipart, and web and email publishing capabilities. When planning a publication in Publisher, it is important to consider the purpose, audience, layout, fonts, and graphics. The program provides templates for common publication types and allows customizing page sizes. The Publisher interface includes a ribbon, rulers, and scroll bars to aid in formatting and viewing publications that can then be printed.