There's aid you have to repay and aid you don't. There's federal aid, state aid, institutional aid. There are Pell grants, Stafford loans and Perkins loans, subsidized and unsubsidized loans. There are funds available through communities, associations and corporations. There's reimbursement from employers.
Some assistance comes in the form of tax credits.
Of course, there are just as many rules and regulations governing a student's qualification for each type of assistance. Adult students don't easily fit the financial aid model. Adult student needs are different. For one thing, your income may be too high to qualify for need-based assistance. Yet you know you won't be able to make it stretch to cover the additional costs of tuition plus books plus childcare, etc.