If you get four years of college paid for because your parent works at a college are you still eligible for financial aid if you need it for living expenses and the cost of books?

Yes, you can. Part of determining eligibility for financial aid is your "cost of attendance" (COA). The COA includes tuition, books, fees, and estimated living expenses. Your total financial aid, including the free tuition you're getting from the school can't exceed the COA. You can receive other aid up to the unmet cost. This will probably be in the form of student loans or work-study depending on your financial situation. The financial aid office can tell you what your options are.