A Basket Of BirthdaysDraw a large basket, then make a red apple for each child. Depending on their age either write or let them write their name and birthday on their apples.
Birthday StarCreate a star for each child's birthday. Make a big star in the center of the board. During the month of the child's birthday put their star in the center of the board. Children that do not have a birthday that month surround the big star. Title the board something like "This Months Stars," "A Star Was Born On," etc.
Great Big Birthday CakeDraw a humongous Birthday Cake (taking up all but the top of the bulletin board) Give each child paper and let them create their own birthday candles. On each candle write the child's name and birthday.
PopcornCut pieces of paper (one for each child) to look like popcorn and put a picture of each of your children's heads on kernel. Next make a popcorn popper and put it on the board. Title the bored something like: "Just Popping By," "Look Who Popped In," etc.