Resume Qs: employment gap and volunteer experience

My last paid employment was several years ago, and not in healthcare (neither were the ones before it). I stopped working in order to start a family, move across country and back (not by choice), and work on my nursing degree--I graduated in May 2009. I have done volunteer work before and while I was in school--about half of it in healthcare or related fields--and I've started volunteering at a local clinic as an RN while I job hunt.

The resume links I've looked through so far don't really address my problem, so I shall ask here: how can I address this employment gap and the healthcare volunteering to my best advantage? Should I have continue to have my Employment experience seperate from my Volunteer experience...or would it be acceptable for me list all of my experiences in a single Professional/Career list, with indicating which ones were volunteer (or do I even have to say they're volunteer?). Or should I focus my resume on my education since I don't have recent paid healthcare experience? Or is there some other better way?