Infoshare is a flexible and scalable information authoring and sharing architecture for multimedia digital signage systems. Proposed architecture internally analyze and classify content, design and system infrastructure into three different layers using metadata extracted by user input and creates a highly scalable and easy to share digital signage environment. Furthermore, this architecture enables decentralized management by defining different user roles to handle each above mentioned layers. We believe that Infoshare architecture can make an efficient Creation, Distribution and Installation (CDI) cycle for multimedia digital signage content while allowing smooth scalability and management of the system. We applied this architecture to a prototype digital signage system.