Eric
From what I observed last couple of times I was there, some of the exhibitors begin packing up shortly after noon on Sunday. Friday is a good day to go because everyone is setting up and once done, they have time to kibitz. Saturday is a mad house and you literally spend all day talking to the visitors. I don't know if it's the common experience, but my table had people 5 and 6 deep, at times, all day Saturday and again most of Sunday morning. I'm looking forward to trying out that side of the table this year...(grin)
Advice for the first time visitor....
Take a decent digital camera (you'll go broke using film) with plenty of flash memory capacity. You do NOT want to be stuck using your cell phone camera there. The level of sensory overload is quite extreme and without photos, you won't be able to recall 5% of what you'll see, once you leave. Trust me on this one.
Comfortable walking shoes... it's a pretty fair sized venue and you'll walk it all, more than once
Cold weather gear... I've been there twice when it was bone marrow chillingly cold. (-19°F with snow and chill factors as low as -60°F) Southern folks just ain't got that kind of wardrobe.
Introduce the SWMBO's ... it helps keep you out of trouble when you get distracted and lose track of time. If they conspire to leave for a shopping trip, just keep your mouth shut...(grin)
Take an insane amount of toy money... many items in the consignment sales area and the auctions (active and silent) will surely be calling your name.
Other things to do...
Amish country is close by and well worth the time for a side trip experience. Damned good cooks too, so try their local fare. Harley Davidson Factory tour... nuff said. Hershey Chocolate factory is near by and a fun tour for the kids. I'm sure the locals can provide even more things to do and see, but these are a few we've enjoyed to the max. Add in several really good local mom and pop eateries and York is a great weekend. When in doubt, ask a local.... they tend to be quite happy to share the local best kepts, even with oddly accented strangers.
Steve