This contribution outlines some new challenges that are faced by libraries and information centers and that are caused by the proliferation of heterogeneous electronic publications accessible through the Internet and the WWW. Methods based on information and communication technology are developed worldwide to cope with these challenges. Some of these are presented with their advantages and disadvantages. The approaches and realizations made in the library of the organization of the authors can serve as a concrete existing example. Access to the electronic sources should ideally be offered integrated seamlessly with the more classical access to hard copy materials in the collection of the library or in collections elsewhere through interlibrary lending and document supply. Offering links that are appropriate for the local user can be achieved through an OpenURL link generator. A recent focus of attention is integration of sources to which access has been purchased by the library with electronic open access information sources that are in principle available even without the efforts of a library. These library services can provide added value in various ways, when users apply this system in their searches for information.