Going for the CPL here. Started four months ago, passed the first six subjects in November, I´ll sit the rest in January/February. I recommend Aviation Exam to hit the question bank, it´s good value. However, there were a lot of unknown questions in my official exams. Not unknown topics, but the questions were different, so you had to know the stuff. Simple learning by heart would not have been enough, especially in Mass&Balance, Performance and Flight Planning.
I have a long and broad aviation background, so things might have been easier so far for me than for the average student. I still started hitting the question bank only after having sat through the Youtube-videos you´ll find for each subject (The Pro Pilot). I´m completely paperless, no big files, it´s all on iPad and iPhone. I did a lot of learning while travelling. The mandatory classroom teaching is good to cover remaining questions. So far about 220hrs, no flying since October. It sure is a big effort and there´s no way I could do it without splitting the subjects.