An initiative to explain High Energy Physics to the general public has been started at CERN. The use of the Web has been identified as crucial to the success of this initiative. An integral part of this project is the construction of a Web-based information system, which collects many different resources on the Web (information published by many European, and US, Particle Physics institutes). This paper proposes a solution to the problem of integration and reuse of heterogeneous information by enriching existing content semantic with metadata in order to improve understanding and discovery. The main part of the work is the study of RDF standard for representing metadata, and its implementation using the XML syntax.