This was my second shelf exam, and I kinda had no idea how to study for this shelf exam. As I was clueless, I didn't solve any questions from any question bank (but if the question banks that the others mentioned are useful for the shelf exam, then I will defer to their opinion. Solving questions always help). That being said....
I thought Case Files, Ambulatory Chapter of Step Up to Medicine, and the USPHTF A/B Guidelines were more than enough to do fine on the shelf exam. I also did have my peds shelf exam before this so I had pretty good knowledge base of peds. But I thought most of the peds questions on my FM shelf could be answered using the 3 resources I mentioned above. Also, I had an incredible family med rotation in which my preceptor taught me a lot and asked me plenty of questions/gave some pearls of wisdom, so that definitely contributed to my overall knowledge base.