This paper reports from a study of use of the dynamic mathematics software, GeoGebra. This study used Ruthven's (2009) Structuring Features of Classroom Practice model to analyse the classroom practices of three teachers in English secondary schools. Here the particular focus is on how teachers manage their resource system with the use of GeoGebra. The main conclusion was that the stage teachers were at in terms of learning to teach with this software indicated differences in regard to establishing a functioning resource system especially in teaching the operation of the software, preparing the dynamic files and the choice of tasks. It became evident that the most experienced teacher was more fluent in managing his system of resources.