At Norwich you will pay for your uniforms (Corps of Cadets). It is around $4000, split into the first 4 semesters. So around $1000 each semester. You will pay for your books, and eventually you will receive your book allowance of around $600/semester. It is to your advantage to pay as little as possible for your books, as you get to keep the difference. You do also get an ROTC uniform allowance at Norwich, cannot remember how much that was or when it came.
My son contracted mid-October, 2 years ago. He had however, passed the PT test in August (scholarship cadets arrive a few days early so they can take the PT test and do paperwork). Not sure what date the kids contracted this year.
As far as what is allowed in your room your Rook year, not much. If you go on the Corps of Cadets page on Norwich.edu, and click around on there, you will find lists of what to bring. Make sure you are looking at the Corps of Cadets list and not the Civilian list. You will need to purchase your boots and dress shoes, sneakers, certain items for Rook arrival day, toiletries, towels, sheets, and a few other things. It is all spelled out on there. You can have a computer, printer (people will love you - you can exchange printing for food!), phone (which can only be used for a 10 minute call on Sundays), clock (not a clock radio).
Feel free to PM me if you have specific questions.