I don't think you are going to get a lot from First Aid in year one. It's a REVIEW book and assumes you know all the concepts. I guess it would be useful to highlight those testable concepts, but that's all first year is about if your school has good board pass rates.
Also, there's clinical concepts that aren't going to mean much to you until 2nd year.
Here's the big secret: if you know your stuff, it doesn't matter what board review books you use. It cracks me up, people swearing by certain books, saying they will make you score higher. It's BS. If you really, thoroughly learn the basic concepts in first year, then add in the clinical stuff in 2nd year (which will make more sense with a good foundation from first year), and do plenty of practice questions, there is no secret information of magical formula in any review book that is going to make any difference in your score, because your foundation will be solid.
Look at the people who do well--most of them do well across the board, starting in first year. That's not a coincidence. Learn from them. Learn from their study habits and how they learn CONCEPTS.
Here's an example. Everyone swears by the MKSAP book for IM shelf exam after 3rd year IM rotation. They all say it's THE book and everyone gives testamonials about how THE BOOK raised their score, yadda yadda. Then why did people who DIDN"T use MKSAP score really high as well? There are several examples at my school to back this up.
The answer is that there is the SAME information in EVERY review book. (Take it from someone who has looked at many of them). The ONLY difference is how the information is presented. And guess what? There is NOTHING in any of those books that (if you go to a decent school) will not be taught to you in first or second year.
So relax about the boards right now. Focus your energy on doing well in first year and learning the crap out of those basic concepts, so you can apply them in second year.
Best of luck to all of you. It's a fun ride...