You worked hard for your basic sciences and now you need to pass the USMLE Step 1 with a kickass score. Fortunately, the resources required for the Step 1 is not as a vast as the Step 2 CK. It all boils down to two resources: USMLE World question bank and the First Aid for the USMLE Step 1 book.
The resources overall:
Dr. Najeeb Videos
Dr. Najeeb videos is gold and I think when you do not know anything, you should start watching those videos first before trying anything else.
Kaplan videos are very comprehensive, but they waste a lot of time reading off the slides to you instead of drawing things out like Dr. Najeeb. The Behavioral science section for the Step 1 is perfect which provides excellent explanation of Ethics and Biostatistics.
Dr. Sattar, from University of Chicago, does a great job smoothly explaining the pathology behind every diseases. He offers an online video course and book to follow along.
First Aid for the USMLE Step 1
This should be your bible for the Step 1 as it has an outline for 80% of what will be on the test. Remember this is not a book so you can not just open it from page one and expect to read it smoothly to the last page. However, make sure you write all your notes on this.
Doctor In Training (DIT)
This DIT course is excellent if you can not figure out how to use First Aid for the USMLE Step 1. This course helps in going back and forth and how and what to annotate on the book to fully understand each and every concept.
USMLE World Question Bank
USMLE World for the Step 1 is the ultimate resource which is a must. It is the most difficult question bank I have ever used but it helped me get a good score on the test. This question bank should be done simultaneously as you are doing DIT and reading the First Aid book.
These are the resources I used and I scored a score higher than the national average for the USMLE Step 1 . It's up to which resources you will use to study for the exam; however, you should note that USMLE World question bank and the First Aid for the USMLE Step 1 book is mandatory to use. This test is not easy and it requires a lot of time and effort so you have to be fully committed to this test, as in you should breath, dream, and live this test.