Textbooks:
I agree with the Hoppenfeld series of books. they're orthopaedic scripture. I bought Hoppenfeld's "Physical examination of the spine and extremities" and Hoppenfeld's "Neurology." Both were great books. The "PE" book is a MUST have for the collection. I bought the "Neuro" book because I was spending some time on the spine service (excellent prep for that). Hoppenfeld's "Exposures" is expensive but good. I wouldn't buy it, I'd just consult it in your ortho library when you need it.
Pocketbooks:
You NEED a fracture handbook.
Koval and Zuckerman is the gold standard here. It was out of print for a few years but they just started printing it again last year.
"Handbook of frx's" (by Perry): The book that I used. Also very good.
I found that the other pocket books like "Ortho. Pearls" and "Secrets" were a waste of time and money.
Review books:
Miller: used by many residents. May be too much at the 4th year student level.
Current Clinical dx in Orthopaedic Surgery (from the infamous "Current" series: This is what I used. More basic, but very complete and hi-yield. Covers everything from basic science to tumor. Very easy read. I highly recommend it.
Baratz (essentials of ortho?): Don't know any thing about it, but one of my classmates liked the book a lot.
With that said, the only thing that was expected of me during my rotations was that I knew my anatomy and basic science. If you can go that extra mile and know things like treatment options, surgical indications, and splinting techniques, you'll destroy your rotations.