How does creditworthiness affect student loans?

We’re writing a post explaining how a person’s credit score (especially bad credit scores) can affect their ability to get student loans. The questions we’re looking to answer include: How good a score is needed to get a federal/private student loan? What kinds of interests rates will people see with good/fair/bad scores? What should a person with bad/no credit who needs to borrow for school do in order to secure financing? What kinds of liabilities do cosigners assume with student loans? What are the risks of accruing student debt with a bad credit score? Requirements: We are looking for experts in student lending, finance, personal finance, banking, credit scores, etc.