This talk will briefly present my PhD research, aiming to contribute solutions to support educators in their exploratory search of (Open) Educational Resources. As a first step, a taxonomy of OER search-related tasks was developed, based on a literature review interpreted through the Information Foraging Theory. The empirical evaluation of the taxonomy allowed to preliminarily identify the tasks to be supported. A series of prototypes, targeting the support of those tasks, were then designed, implemented, and evaluated, following a modified Design Science Research approach. The features of the last prototype, Discoverer, include: (1) the possibility to transparently carry out specialized searches directly from Google result pages, (2) the possibility to identify resources similar to a sample resource (query by examples), (3) a similarity metric based on educational alignments, and (4) clustering of results in expandable classes of different degrees of similarity. The feedback from 29 educators from Italy, UK and Brazil, involved in the summative quantitative + qualitative heuristic evaluation of Discoverer, was very positive. They appreciated, in particular: (1) its support for exploratory search, (2) its strong domain-orientation, and (3) its direct support for Work-Context level tasks, such as lesson planning for personalized education.