Yuck, 3rd brigade. As Auto said get the MOI, try to get the new one so you know the date and time is right. On the opening page of armystudyguide there's an actual downloadable PDF file that has the majority of questions asked.
Standard topics are covered are on the MOI, but you always need the NCO and Soldiers Creed, Unit History, Crests, DUI, Unit Awards. I would recommend the 7-22.7 for basic NCO discussions, and knowing your primary weapon.
Practice your creeds and autobiography at the POA. If you can gain access to where the board is held, practice reporting and your movements. Always get with your leadership for their experiences and to set up MOCK Boards.