In eLearning context searching for suitable educational material is still a challenging issue. During the last two decades, various digital repositories, such as Learning Object Repositories, institutional repositories and latterly Open Educational Resources, have been developed to accommodate collections of learning material that can be used for instructive and research purposes. In order to make this learning material publicly available through internet searching mechanisms, it has to be enriched with metadata. Nowadays, emerging Web 3.0 applications necessitate further enhancing learning resources with semantic knowledge to facilitate conceptually searching. Adding semantic value to educational resources could be achieved by modeling ontologically the metadata profile which describes them. The purpose of this work is to demonstrate the process of enhancing semantically learning resources by developing a new ontology and a prototype system to accommodate them. The designed ontology is originated from a metadata profile which is build according to the guidelines posed by Singapore Framework for Dublin Core Application Profiles. We focus on educational material for teaching courses on Informatics in primary and secondary education in Greece but the methodology and mechanism introduced could be easily adapted in any domain-specific setting.