I read The Last Last-Day-of-Summer out loud to my son in the days leading up to his first day of 1st grade. We both loved it. Some of the jokes and references were over his head, but he was generally able to follow the plot and was beginning to continue reading at the end of each chapter.
The two main characters are Otto and Sheed Alston, Black cousins famous for their otherworldly adventures in their unusual town. They are extremely close and both live with their grandmother (why this is or where their parents are goes unmentioned) and their main competitors are two Black sisters - one a wizard at robotics and the other nicknamed "Wiki" for the vast amount of knowledge she carries around in her head. There's a nice aside at one point where Otto recalls his grandmother's reminder never to touch anyone without their permission - even if their body is frozen in time - and asks Wiki if he can touch her arm to unfreeze her.
The book is a long and engaging read full of adventure, traps, "manuevers" to escape tricky situations, complex relationships, and richly drawn characters. We're already eagerly waiting for the next book, and though we borrowed this from the library it may be one of the few we purchase to keep on the bookshelf for years to come.
BUY HERE (or, even better, request at your local library)