The Office of Student Financial Assistance links to the FAFSA application and other loans. Keep in mind that some loans may not be disbursed until you have registered for classes. Many graduate students do not apply for loans until fall semester—deadlines listed on the FAFSA website typically apply to undergraduate applications, not to grads. As will all business connected with being a grad student, check your dates and deadlines carefully.
The GradGrants Center is a great resource for graduate students seeking financial aid. This site has links to job listings for academic postings, searchable funding databases (you need a university username and passphrase to access these), other granting resources, and information about external fellowships frequently awarded to IU students. Many anthropology graduate students are eligible for FLAS Fellowships.
The GradGrants Center also offers one-on-one proposal drafting advising sessions with their award-winning consultants. These are available in-person or via web conferencing for any external (non-IU) funding opportunities.