Constructing Knowledge Base Systems using pre-existing generic components rather than from scratch is a promising way of minimising development time and facilitating evolution and maintenance. The concepts commonly used in describing KBS are tasks, PSMs (problem solving methods) and domain knowledge. Developers have to select them from a library, then adapt and link them so that they fit their specific needs. In order to help developers to quickly understand, find, and configure the components1 best suited to their applications, we need to specify languages for describing the tasks, PSMs and domains2 plus the different interactions between them. In this paper, we describe a methodology for structuring a library which has different components and relationships defined through levels of description: metaontology, ontology library and application. We propose the use of semantic and transfer links — often applied in databases systems and object modelling - to specify the relationships between tasks, PSMs and domain knowledge and to use ontologies to describe these concepts, improving thus their reusability and shareability.