Confused again about why board exam prep is listed here? Step 1 is in the rearview mirror, and maybe Step 2 CS/CK as well. However, all US medical graduates will have to take Step 3 at some point and trust me: sooner is much, much better than later. USMLE Step 3 is a comprehensive exam that covers all the same topics as Step 1 and 2, but with more clinical applications. Additionally, the exam is longer, requiring two separate days to complete.
Okay, that got intense - on a lighter note, the second topic is of more interest to your future career. As you prepare for interviews, you should have a good idea of what your field is about and what you need to do to prepare. If you are still figuring out what to apply for, Iverson will help narrow that down as well.
While the Iserson book is somewhat dated, it is still an excellent resource to refer to as you go through the process, as Iserson provides a good system for comparing programs to each other on the interview trail. Additionally, this site had a series of posts in the past dealing with residency interviews: Residency Interviews Tips, Parts 1 - 5. The posts are quick easy reads with the intent of providing high-yield information for interviewees.
Enjoy fourth year! Good luck with residency applications!