Board books make it easy to read to babies and toddlers.
They are almost always sized for little hands, and if a reader chews the pages it doesn't really hurt anything.
At our house, favorite board books include Margaret Wise Brown's Big Red Barn and Good Night Moon. We also enjoy a little set of four books from Baby Einstein: Babies, Dogs, Birds, and Cats. Each of these four books includes a picture of an appropriate baby, dog, bird, or cat drawn by a child, as well as a variety of descriptions with accompanying art: babies crying, or dogs chasing Frisbees.
A lot of the books older children enjoy have been adapted to a board book format. In some cases the text has been shortened but the illustrations are often the same. Look for stories like Watty Piper's The Little Engine That Could.
Whether you have regular small visitors or just occasional ones, board books make a good addition to your home library.