I would highly recommend having less than 10 sheets of reference material MAX. Any more than that and you are going to overload yourself when you are reviewing notes or using them during practice.
Notes are great, but practice is key. Crank out MCQs and sims as you are studying. Even if you start to memorize the answers you will be doing yourself good by seeing and thinking about the questions and answers.
To sum it up, everyone is different but your number one way of retaining the information is by practicing it. I only had a handful of reference sheets during my study time. I NEVER looked back at my actual notes (I took notes because writing things down as I read helps me retain the information).