Rote 8, people vary quite a lot. I did the old CAA exams so things may be a bit different, but not that different. For the navs, I did about 10 hours a week for a couple of months, then a month's course at Bristol, then 2-3 hours a day for the two weeks before the exams, and passed 7 out of 9. I knew people who did a lot more, and some who did less. For me, fairly short but concentrated work periods with breaks worked better than long periods where the stuff would go in one ear and out the other; I have to learn a lot of new stuff in my day job too, so I felt as though my brain was constantly close to overload if I tried any other way. I also found it better to read it all through and get a general feel for it, then go back and learn it properly. But some people would say the complete opposite. You need to find a study system which works for you. It may be useful to make yourself a plan of what you want to have learned in a particular time period, then see if it works. If it does, fine. If not, you need to do more, or study differently, no matter what anyone else is doing.
Hope that helps and doesn't just confuse!