Just took mine today, so I don't know how I did (although it felt like it went well......but I've been wrong before). Here's what I did and what many people do:
Use First Aid (get 2006 or newer since it's in organ system format instead of basic science discipline format) as your central resource. Then take a few books that are specialized and annotate FA with notes taken from them. For example, I used BRS pathology, BRS phys, and Medical Microbiology Made Ridiculously Simple. I would have FA open to the cardio phys section as I was going through BRS phys. Anything that seemed important that wasn't in FA but was in BRS I would add in to the margins. The same went for Path. All three of these books were more than adequate in my opinion. I didn't get tested on anything that wasn't in these books.
One pitfall that is easy to fall into is using too many resources. For one, it's expensive. Secondly, getting bogged down in details out of three different path books will use time better spent getting a broader overview of more diseases. Each book will focus on a needless detail for every disease, but they will all cover the important details. Using three books means you still learn the one important thing but you've now also learned three needless things.
From my time going through this I believe First Aid is adequate for biochem, stats, pharm, and embryo/anatomy. The path section needs to be suplemented and the physiology sections need to be supplemented. The bacteriology section needs to be supplemented as well (fungi and viruses is probably adequate).
If I had it to do over again I would get USMLE World. From what people on here say it is more closely aligned with the real test. Qbank focuses on too many small details that never get tested on (the pharm section on qbank is absolutely ridiculous and is so far from what step I is like it's not even funny). Also, World is cheaper I believe. One month of world is $75.
Of course all this is my opinion, and you're going to get a million different opinions from a million different people when it comes to preparation for Step I. However, I think most people would agree the best way to prepare for Step I is by working hard during the first two years. There's a cummulative knowledge that builds over time that you can't just create in the matter of a month or two of cramming.