Blades of Glory by John Rosengren is a nonfiction book about a youth hockey team. Unlike the major literary works that are usually assigned in English classes, it is not the subject of much in the way of critical studies for two reasons. The first is that although it provides important information about young hockey players in Minnesota in 2003, that is not a topic of universal interest, and like most journalism, became dated soon after publication. Second, it does not have the literary qualities that would make it a book of timeless interest. Thus the sorts of resources you will find concerning it are of two kinds, reviews, mainly written in 2003 or 2004, and promotional materials.
You can find customer reviews of the book on Goodreads and Amazon.
The most detailed material available on the book is found at the author's own website.
Realistically, though, it isn't the sort of book one actually needs help understanding as it is a straightforward nonfictional account of the lives of the young men on a school hockey team. The best way to follow the book is to take good notes as you read it. The aspect of the book most likely to be confusing to a reader is the sheer number of characters. The best way to keep them straight is actually index cards.
Every time you encounter a new character as you read the book, write down the character's name and the page numbers on which the character occurs, along with a brief description, on an index card. Keep the cards in alphabetical order, so that you can conveniently look up characters when you encounter them again. You also might create your own timeline of principle events as you read as a way of structuring the information in the book for later study.