My boyfriend and I are both students/research assistants and we just got a puppy this summer. I would recommend to get a puppy during your school breaks, so you can have days off and take care of the new puppy. We got our puppy in July and we were able to go home during lunch time or just work at home during summer. I can't imagine dealing with all new puppy things during the school year.
1) We contain the puppy in his exercise pen, 4 by 4 ft. and leave down two pee pads for him to use during the day. He usually use one and make snow with the other one, haha. Pee pads are much cheaper at Meijer/Kroger/Walmart/Online.
2) We are first time dog owner... Not much experience, but any food for small breed puppy should be okay
Our dog food is chicken and rice based, it is easy on the stomach according to our vet.
3) We use the bell method. It works well. Our puppy sits by the door or hits the bell when he needs to go. It took about one week for him to get the idea and about one month for him to do it more consistently. I feel another important thing is to catch him/her when he/she is doing it inside and bring him/her outside right away. Our small apartment actually made this easier :P as he doesn't have too much room to roam around.
4) 10 on food, 20 on preventative meds for worms and flea, 10 on pee pads, 20 on toys (he destroys his toys...), ~60 for each wellness exam and shots (totally 3), 30 on insurance. Yesterday, we just spent ~100 as our puppy had vomiting and diarrhea... I'd say $150 -$200 /month for the first 6 month... I hope it gets cheaper when he gets older... Definitely cost more than what we thought, but still affordable if you find the stuff at the right place (pet store is always more expensive).