We make a calendar every month. I put one child's name on each day of school....so we just have one s and t kid per day--unless someone forgets one day. Then the next day we'd have two show and tells.
I leave it pretty WIDE OPEN but I do tell the kids that they can bring only ONE thing. Some kids still bring more than one thing and I tell them to choose one before our s and t time otherwise it gets out of control.
I firmly believe that the oral language part of it--regardless of the mundane or ridiculous toy they bring in--is so very important and a valuable building block in a child's confidence and ability to speak in front of others.
From Sept to about the middle of October we don't have s and t. Instead I interview a different child each day--Patricia Cunningham stuff. Then we start the show and tell in mid October. By the holiday break in December each child will have had two show and tells.
In January we might start a Mystery Can. Again, we make the calendar...one child each day brings a coffee can home with a little notebook in it. They have to choose something that will fit in the coffee can and write three clues as to what they've put in the can. They read the clues, one at a time and choose a child to guess what it is (one after each of the first two clues). After the third clue, the show and tell kid can call on THREE people to guess. If we still haven't got it, they reveal what they brought in. It's a lot of fun!
If someone guesses the mystery item, they get to write their name in the notebook on the same page as the three clues so that we know who guessed the mystery item!
I use Mailbox.com's pdf calendars. I either fill it out online or print it out and write in children's names and special events that will happen that month. I always write SHOW AND TELL CALENDAR in an empty space.
This calendar is stapled on the bottom half of a 12x18 inch piece of construction paper. On the top half, the kids do some sort of art project.
In October, the kids made a jack o lantern with construction paper, grass, moon, trees, etc. These were all glued on black construction paper. I type up a little poem each month that the kids also glue onto their project. "I made this scary pumpkin for everyone to see. It looked so big and terrible it even frightened me!"
November...a turkey on the farm...."Gobble gobble turkey. Run while you can. Or someone will catch you and put you in a pan!"
December....(no poem) We make the letters J O Y....J is white. We make red stripes on it so it looks like a candy cane. The O is green....we turn it into a wreath with a little ribbon and some glitter berries. The Y is brown....a reindeer. We put google eyes and a red pom pom nose on it.