You have 9 hours to do a 15 minute tutorial, finish 8 hour-long blocks, and squeeze 45 minutes of break time where you choose. You can get an extra 15 minutes of break by skipping the tutorial. Every minute of break that you go over your allotted time is a minute that you take away from the last block. I don't recommend going over. By the last block you will feel whipped, and you don't want any disadvantages on the final stretch. I found that short breaks work well to recharge, but if I took too long of a break I would start to lose momentum.
As for lunch, take it when you are hungry. I tried to do two blocks consecutively if I had the energy. I think I did 2 blocks, 5 minute break, 1 block, 5 minute break, 2 blocks, then lunch. This left me with only 3 blocks to go after lunch. But you should do what works best for you.