It’s always someone’s first time. For every convention, there’s someone there for their first time. And it might even be their first convention. (There’s also someone there for the last time, but you won’t know that right away. People have a limited attention span, though, so you should realize that attrition happens.)
Same goes for being a volunteer, or being on staff. There are people signing up to help who haven’t been involved before, and probably someone who’s not going to be involved anymore.
How easy is it to get your bearings the first time? A lot of first-timers will immediately take their program book and schedule out of their reg bag, and sit down to start reading it cover to cover, or at least for as long as it takes them to find something they want to stand up and go see. Do your printed materials help them to do that? If you’ve decided not to have printed materials, what do you have instead, and is it as easy to use as what it replaces?
And for people who have decided to volunteer for the first time, either at-con or premeditatedly. Can they figure out what steps they should take to be useful? What about people who want to join the staff, what should they do first to get into the system? You should also convey what volunteers and staff get. This is doubly important if those perks have changed since last year, because you should be thinking of how to let returning staff know that the deal has been altered.
Do qualified staff people get comped badges, rooms, meals, t-shirts? Do volunteers get credit towards a pass-on badge or a reimbursement? Valuable prizes?
What do you want the staffer or volunteer to do, and what do you do for them?