I was flying the A320 in the UK for 6 yrs on a CAA CPL/IR and had to do all the JAR exams without exception.I aquired the PPSC notes on disk and also most of the OATS study books.The oxford books are essential and with a lot of feedback questions along with the 2 week brush up course at Bristol I scraped passes eventually in all subjects within 7 months.The knowledge and experience you have as a current commercial pilot will take you through 5o% of the exams.