Do you want to understand how IELTS works, how to prepare students for IELTS and what to do in your lessons? If so, you can take a look at these English Language teaching journals and choose IELTS articles which interest you.
In one class you should cover 1 graph type. For instance, one lesson on a line graph, another lesson on pie charts. Here are the stages you can follow during your writing class (you can change the order of the stages if you wish):