When I took out loans, I took out an extra $2000 or so per semester (when I didn't have a job to supplement my income). If you are in a program that will lead you to make enough to easily make your loan payments after school, I would recommend not living the poverty-type lifestyle for four years of your life.
The way my loans worked, I think I had a maximum allowance of $5,000 per semester, but all of the money has to go through the bursar's office so that they know you aren't just pulling out 50k+ and screwing around with it.
You can take out up to the cost of attendance. This amount is set by the school using a formula given to them by the Department of Education. The amount varies widely based on location. For example, here in DC my loans this year are $11,xxx.xx more than my tuition each semester. However, when I was in SC the number was more in the $6,xxx.xx range. (IMO, you take out full amount if they are subsidized loans and only take out need if unsubsidized.)
The federal government has laid out certain things that you can increase the cost of attendance for. For example, there is a laptop allowance of ~$1500 if you present a receipt for buying a new laptop. There is also an exception for your kid's daycare. I don't know the full list but I'm sure you can find it. If you have expenses that fall under one of these categories you can contract your financial aid office and ask for the correct paperwork to fill out in order to get approved for the extra ammounts. Normally you have to present receipts to prove you actually have the expenses.
this is getting annoying I sign my MPN already, called the office, looked to see if I missed something. Other then a Cosigner (which I cannot aqquire for the life of me.) I don't have a clue why I only got enough for half time reg.