I took an IB course a year ago with its exams on the end. The course took place at my secondary school and was fit into my regular program (my secondary school was bilingual Dutch/English and this was obviously one of the English topics). As a group we had to choose two main subjects at the beginning of the course on which we would concentrate. During the course, we had two lessons in a week. One lesson was more or less dedicated to writing and speaking (mostly writing actually). The other to reading and listening. The teacher had a huge variety of assignments for us, sometimes with strong and structured help. Other times we had these individual essays on topics chosen by ourselves. We used articles from newspapers, internet articles, and magazines to get inspiration. From time to time, the teacher would collect a selection of the writing products and corrected them. We also had to do some presentations or debates to test the speaking skill as well. Finally, we had to write several articles, both literary and non-literary, read three literary books, give several presentations and oral exams on the books e.g., and make three exams. If all the marks (marks were given from 1 to 5) were sufficient enough, we passed.
Both the teacher and the students had to agree on the books that were allowed to be read. I read as an example:
Nevil Shute - On the beach
Charles Dickens - Great expectations
Mary Shelley - Frankenstein
I hope this is the information you asked for. If it was any help, please ask me whenever you like for more information.
I am (unfortunately) not a teacher.