How can one help take care of a family member that have alzheimer's?

Get informed. It is helpful to any full time caregiver and to a person with alzheimers for others to be involved. Contact the alzheimers foundation or the alzheimers association to become informed about specific caregiving techniques. Remember that the primary memory deficit is inability to form a new memory. Recognizing this can be helpful as you work with people who have this illlness.
Give carer a break. Caring for loved ones with alzheimer's disease is a 24/7 job, and many carers must hold down full time jobs as well. As a result, carers are often exhausted and depressed. The best thing you can do for a patient with alzheimer's is to give his/her carer a break.