UNAIDS - Joint United Nations Programme on HIV/AIDS 

Raise awareness, raise funds, volunteer for your local HIV/AIDS organisation or join the fight against discrimination and prejudice. From protecting yourself and your partner with safer sex and getting tested to caring for people living with HIV/AIDS in your own community, anything you can do will be a valuable and welcome contribution.

Talk to your family and friends about HIV, AIDS and safer sex: Ensure you and your partner discuss using condoms - protect yourself and others.

Young people in many parts of the world are denied sex and health education in schools because parents and other authorities fear it encourages early sexual activity. But there is compelling evidence from studies conducted around the world and in many different cultures that, in fact, sex education encourages responsibility. Experience shows that peer education, which involves training representatives among out-of-school youth to convey information, is one of the most effective strategies.
Because of its association with behaviours that may be considered socially unacceptable by many people, HIV infection is widely stigmatised.

People living with the virus are frequently subject to discrimination and human rights abuses: many have been thrown out of jobs and homes, rejected by family and friends, and some have even been killed. Together, stigma and discrimination constitute one of the greatest barriers to dealing effectively with the epidemic. They discourage governments from acknowledging or taking timely action against AIDS. They deter individuals from finding out about their HIV status. And they inhibit those who know they are infected from sharing their diagnosis and taking action to protect others and from seeking treatment and care for themselves.

Experience teaches that a strong movement of people living with HIV that affords mutual support and a voice at local and national levels is particularly effective in tackling stigma. Moreover, the presence of treatment makes this task easier too: where there is hope, people are less afraid of AIDS; they are more willing to be tested for HIV, to disclose their status, and to seek care if necessary.

http://www.unaids.org/en/GetStarted/YoungPeople.asp