Resumes and Cover Letters: Are there formats for RN?

Hello all! I am looking for advice on proper Resume and Cover Letter format. I will be relocating this summer to the East coast and therefore need to find a new place to work. I haven't touched my resume in years. I have a total of 6 years RN experience, almost 4 of which has been in Trauma ICU.
Now, I'm not sure what is too much detail, not enough detail, or obvious enough that it doesn't belong in the resume...

Any advice/suggestions would be greatly appreciated!