The authors of topic map-based learning resources face major difficulties in constructing the underlying ontologies. In this paper we propose two approaches to address this problem. The first one is aimed at automatic construction of a “draft” topic map for the authors to start with. It is based on a set of heuristics for extracting semantic information from HTML documents and transforming it into a topic map format. The second one is aimed at providing help to authors during the topic map creating process by mining the Wikipedia knowledge base. It suggests “standard” names for the new topics (paired with URIs), along with lists of related topics in the considered domain. The proposed approaches are implemented in the educational topic maps editor TM4L.