This paper presents project Nomage, which aims at describing the aspectual properties of deverbal nouns in an empirical way. It is centered on the development of two resources: a semantically annotated corpus of deverbal nouns, and an electronic lexicon. They are both presented in this paper, and emphasize how the semantic annotations of the corpus allow the lexicographic description of deverbal nouns to be validated, in particular their polysemy. Nominalizations have occupied a central place in grammatical analysis, with a focus on morphological and syntactic aspects. More recently, researchers have begun to address a specific issue often neglected before, i.e. the semantics of nominalizations, and its implications for Natural Language Processing applications such as electronic ontologies or Information Retrieval. We focus on precisely this issue in the research project NOMAGE, funded by the French National Research Agency (ANR-07-JCJC-0085-01). In this paper, we present the Nomage corpus and the annotations we make on deverbal nouns (section 2). We then show how we build our lexicon with the semantically annotated corpus and illustrate the kind of generalizations we can make from such data (section 3).