At my test center I was given 2 sheets of laminated paper and two markers. The markers were not erasable so you had to ask for new sheets if you needed them and they take the old ones. I didn't need new ones at my 15 minute break, but I traded mine in anyway just in case and got fresh clean sheets.
There is one break after you complete the natural sciences and PAT section that lasts 15 minutes. It is optional, but I would advise taking full advantage of it. Also, if you complete a section early and you have finished going over all of your marked questions you can take a break before you move onto the next section. I finished my natural science section and reviewed my marked questions and still had about 7 minutes left, so I got up and walked around a bit.
My test center had two "labs" full of cubicles and there were headphones at each station to help keep out the noise. I found that even though it was quiet, there were people all around me typing so it was nice to have the headphones.
All of your personal belongings have to be locked up in a locker. They check your pockets and do a scan with a metal detector before you enter the test lab. If you leave to take a break they make you do it all over again when you come back in, so make sure you give yourself a few minutes when you are on your 15 minute break. I had to sign in and out, and they even had a fingerprint scanner to make sure it was really me when I came back.
The best advice I could give is to stay calm and relax during the test. Use your 15 minute tutorial to set up your scrap sheets the way you want, since you can't erase during the test. I drew out my boxes for hole punching and made up my tables for cube counting during the initial tutorial. Take full advantage of your break to recharge. Good luck!
