EuSpRIG concerns direct researchers to revisit spreadsheet education, taking into account error auditing tools, checklists, and good practices. This paper aims at elaborating principles to design a spreadsheet curriculum. It mainly focuses on two important issues. Firstly, it is necessary to establish the spreadsheet invariants to be taught, especially those concerning errors and good practices. Secondly, it is important to take into account the learners' ICT experience, and to encourage them to attitudes that foster self-learning. We suggest key principles for spreadsheet teaching, and we illustrate them with teaching guidelines.