What should I take to BCT? ?

Do I need a duffle bag for personal items or should I be able to fit everything in the issued Army backpack? What is given to privates as far as toiletries? Do I need to bring my own shampoo, toothpaste, ect? What about socks and undergarments? Other than the clothes I wear to the air port should I bring civilian clothes? I go to AIT immediately following BCT. Do you have any organization tips? Thanks : )