How the pool works varies GREATLY from facility to facility. What I am familiar with is that the "pool" positions are per-diem which means it is not a benefited position but they have premium pay. You are "scheduled" for certain days.......but are amongst the first to be cancelled if census is low. YOu will ahve holiday obligations determined by the facility. It is possible to work 40 hours, if you are cross trained for several areas like Emergency department or critical care areas as well as general medical. It is also helpful if you are willing to work anyshift and last minute calls. You will receive less cancel time in larger facilities with more clinical areas and potential for sick calls.