Boards didn't work very well for me. At least not alone. A cork board (that you can divide into sections for each child) might be good, but you'll need somewhere to put papers that have to be signed/returned also.
(from picture day payments, to field trip permission slips, to sign ups to bring this or that, to graded papers, etc... there will be TONS of stuff that has to go back by x date---for each child).
What I never managed to remember to do (until I did online virtual school last year) was to get a vertical slot thingee. I don't know what you call them, but for homeschool (not quite the same needs) I got the vertical magazine holders and set them on my desk. Each child's folders for various things went into it, for easy access. Along with my own daily planner.
For returning papers and such to school, what I think would be ideal would be one of those mail/letter things, that you keep track of bills with. 30 vertical slots just wide enough for a few pieces of mail each (or something like that). You could label slots M-F for each child, and put any paperwork that needs to be returned in the appropriate slot. Set it under the corkboard near your exit for school. As you head out each morning, you can check (or the kids can) to see if anyone has anything due that day.
You do end up with flyers and things that really just need to be stuck on a cork-board until the event is over. You could probably get a dry erase calendar with the cork-board strip across the bottom. Use the calendar to write stuff on the appropriate dates, and the cork strip to tack up the associated flyers (with all the details pertinent to the events). Then have the slots underneath on the counter for things that have to go back to school.
As for papers coming home? I have 2 drawers in a side board that are full of such items. Every year I think: "I need to go through that stuff and trash most of it", but I never get it done. I saved almost all of my son's kindergarten papers. I was glad later, because it gave me hard evidence of his handwriting struggles and exactly what he was (and wasn't) doing... when my brain just couldn't remember the details any longer. :)
And when they are older, they might enjoy reading some of their short stories and sentences, etc.