Courses and materials in Claned are set up into boards if you are not the creator of the board you need to be be invited to it in order to access it or be part of a group which has been given access. In both cases, access is granted by the board administrators. If you are not seeing or able to access a board, contact your administrator or teacher directly and insure that they have the correct information about your account - email address and user name, and that they have added you. If you have created your own board and others are not able to located it make sure you adjust the visibility settings in the the "edit board sharing" to either "public" or "invite individual users" and invite them.