Share time is when you go to visit a unit and follow a nurse around and see what its really like to work there. Try to notice the non-verbal communication-does the nurse look annoyed that she has to show you around? How well do the doctors and nurses communicate? Ask about lunch and potty breaks. How do they handle lunch breaks? Are they assigned coverage or is it a free for all (which means you most likely won't get one)?
Most of all listen to your gut reaction. Do you get a good vibe from the staff and you enjoy being there? The units I visited (and worked on) I enjoyed visiting and could have stayed all day. They made me feel at ease right away.