Good luck in your new job! ER is definately the way to go. I don't have any recommendations on books, but I do suggest you get a PDA with some ER related and med related software. I use my Davis Drug Guide (buy online) or Epocrates (free online) every single day.
When you are in triage and assessing patients home meds, you will always hear of a med that you need to check spelling
on, or supply some sort of info on. I am always looking up a drug for myself, a co worker or a patient.
ER suite is a good software to purchase. It has lots of good info as well.
You can check with co workers who have some of the programs they can "beam" to you as well. I have Merck manual which is also free, and Tabers that I paid for.
You will still find things you need to look up and the PDA makes it easier and faster than finding a reference book.
Also, if you don't already have ACLS, PALS, ENPC, TNCC...try to get them all as soon as possible. They all offer a little different information that you will find valuable.
One word of advice from an old timer....don't be too quick to judge your co workers when they complain about someone being a drug seeker, frequent flyer, etc. Walk a mile or so in our shoes before you critisize.
Give yourself time to learn this new area and don't be too hard on yourself while you are learning. It is a different pace with different challenges than other areas of nursing. You need to know a little about EVERYTHING, but you don't need to know evverything about everything. You never will become a specialist in the ER, but you will learn so many things it will make your head spin.
The longer I am a nurse, the more I realize I don't know, so take a deep breath, jump in and learn!