The Classic Fantasy rules of Old-School Essentials will be used. Some Advanced Fantasy rules will be brought in and listed along with any house rules.
This will make the game very close to the B/X style of play.
The Classic Fantasy rules are listed in the Rules Tome (one book) or the Classic Game Set (5 books). The rules are the same, the box set just splits the single book into multiple smaller books.
Old-School Essentials also has their SRD online with most (all?) of the rules available there.