Learning from the book is a waste of time. You should not be reading cover-to-cover and trying to learn from it. The First Aid for the USMLE Step 1 is not a learning tool instead, it is a outline for what will most likely be on the test. The First Aid should be used in conjunction with USMLE World question bank. Of course you should memorize the First Aid book cover to cover but only if you learned the materials beforehand. When you understand the medical concept then memorizing it is so much easier. I strongly recommend you go over First Aid book with Doctors in Training after you do one round of USMLE World question bank.
Make sure you get the latest version of the book. Get the First Aid for the USMLE Step 1 2013 version if you are just starting out. It's not out yet but you can pre-order it when it comes out in January 2013.
Honestly, I was lost when I was reading the book, but Doctors in Training (DIT) program helped a lot get a good grasp of the materials covered. I will write detailed reviews of DIT and USMLE World question bank in a later post.
I probably read in detail each and every page of First Aid more than ten times. I wrote a lot from USMLE World and other sources. If you look at the pictures you can see that I had I hole punched and ring-binded so it would be easier for me to flip through it. Also, if I needed extra space to write in some information, I can just add ruled paper or if I need to draw a diagram I can add printing paper. Basically, I did what I needed to do in order to fully study comfortably.
Do your best to understand and memorize all the concepts in the First Aid book, because it has everything you need to get a great score on the USMLE Step 1.