In this paper we present the methodology of data collection and implementation of databases with the purpose to create extensive lexical and terminological resources for the Greek Sign Language (GSL). The focus is on issues of linguistic content validation, multipurpose design and reusability of resources, exemplified by the multimedia dictionary products of the projects NOEMA (1999-2001) and PROKLISI (2002-2004). As far as data collection methodology, DB design and resources development are concerned, a clear distinction is made between general language lexical items and terms, since the creation of resources for the two types of data undergoes different methodological principles, lexeme formation and usage conditions. There is also reference to content and interface evaluation mechanisms, as well as to basic linguistic research carried out for the support of lexicographical work.