Chelsea Clinton has locked down her next book. The best-selling children’s author has reteamed with Penguin Young Readers to publish Start Now! You Can Make a Difference this fall, EW can exclusively announce. The book —featuring facts, stories, and tips on how to change the world — will be aimed at readers ages 7-10 years old. Clinton will use her platform to break down issues relating to health, hunger, climate change, endangered species, and bullying for young readers to understand, and see how they can make a difference in their own lives, as well as in their communities and the...