I asked the same question a few months ago, and ended up getting converted to the field. 🙂
I found the Michigan Manual very, very helpful. Once I decided I was going for plastics I bought Secrets (which I've been reading through slowly-- it's much more in depth). The UTSW book also looks great; I flipped through it but it was a bit pricey. In case you need to give presentations I recommend checking out the recent copy of Grabb & Smith from your library for the month, so you can plumb the depths of a topic more quickly.
I'm sure the PRS residents on the board will know of other books, but the aforementioned ones really helped me out when I was on my sub-i and still planning on applying in gen surg.