Brad,
All financial aid is generally arranged through the financial aid office. As a medical student, you can borrow up to $38k or so in federally-guaranteed Stafford loans every year. These loans aren't dependent on credit; you're guaranteed them as long as you haven't defaulted on previous student loans or exceeded your loan cap.
If the financial aid office determines that your total cost of attendance will exceed that, you can arrange for private loans at slightly less favorable terms to cover the balance. If you're going to a public in-state school, though, the Staffords should cover the sum total of what you need.
While there are some categories you can't use the loan money for (credit card payments, car payments, etc) anything that constitutes a reasonable living expense is covered. So you don't really need to worry about navigating between, say, tuition loans and housing loans. They're all lumped together.
Med schools want to make sure that you don't have to worry about just the sort of things you've mentioned. The school I'm matriculating into automatically deducts rent for its on-campus housing from the financial aid package, for example. As long as you remember to pay your bills on time and don't live extravagantly, money isn't really an issue until, of course, you start repaying it!