We are always thankful for anyone that spends their time as a volunteer at Phoenix Children's Hospital. Here's the link to get started: http://www.phoenixchildrens.com/ways-of-giving/get-involved/volunteer/
You can request the area you want to work. I think it is extremely helpful to be in the area, see how the unit works, ask lots of questions of the staff (and generally be helpful). That's always a good way to learn. It may not be nursing experience per se but you will have a basic understanding of a lot of stuff after working there a while. For example, you will learn how to make the bed rails go up and down, how the bed locks, how to transfer a patient to and from a bed, what sounds mean what (i.e. alarms, etc.). These are all things that are very foreign to someone who has never worked in a hospital before.