This is going to depend on the type of book you have. Paperback books will be the hardest to clean because of their inherently delicate nature. Getting the pages wet can cause permanent damage so proceed with caution. With hardback books, you can wipe down the covers with a damp cloth and then immediately follow with a dry cloth or paper towel to prevent moisture damage. The easiest books to clean are board books. Their durable design allows them to withstand moisture far better than the other book styles. While you shouldn’t immerse them in water, you can wipe the pages clean with a damp cloth soaked in cleaning solution — and follow with a dry cloth to remove excess moisture.