Depending on your organization and the demographics of the students you are collecting books for, you may be eligible to purchase from First Book, which provides a steep discount to organizations providing books for students in need. Here is more info:
https://www.fbmarketplace.org/register/
I would add to the awesome suggestions above:
Kalyn Baron’s The Vanquishers series
Sharon Draper’s The Clubhouse Mysteries series
The Tales from Cabin 23 series
Picture books by Derrick Barnes
Books illustrated by Christopher Robinson (like Last Stop on Market Street, Milo someth8ng…)
The Abbey in Orbit series
Nic Stone’s book Clean Getaway
Kwame Alexander’s books (fiction and picture books)
BB Alston’s Amari series
Nic Blake trilogy by Angie Thomas
Let us know if you need nonfiction too.