Depending on the number of iPads you will have in your ensemble, your needs in terms of "fleet management" will differ. Because using iPads for sheet music is fairly simple, the only maintenance your devices should need after initial setup is to keep the operating system (iOS) and the apps you use up-to-date.

This can be set up to be done automatically, it can be done manually by the musicians themselves or by dedicated staff, or it can be done remotely via a Mobile Device Management Solution (MDM). While not absolutely necessary, an MDM solution can help save time, and adds more security by enabling your to lock the devices remotely in case they are stolen, etc. 

Of course, in addition to keeping the operating system and apps updated, you will have to make sure that the iPads are fully charged before rehearsals and performance! Different organizations have adopted different approaches for this: some will leave this responsibility to the iPad users (musicians/singers/stage managers/librarians/etc.), whilst others will take care of it by gathering all the iPads at the end of each rehearsal and storing them in a charging cart.