https://knowledgequest.aasl.org/free-online-books-for-elementary-students/ - a comprehensive list of books online for kids, as well as PD links for you!

http://amazingeducationalresources.com TONS of links - almost too many!

https://www.penguinclassroom.com - Penguin Random House Publisher book resources

https://www.rhteacherslibrarians.com/latest-buzz/updates-and-resources-for-educators/?ref=PRH7D30672AB3 - Random House Publisher book resources

https://www.mackidsschoolandlibrary.com - MacMillan Publishers book resources