It's World AIDS Day. (Chad Baker/Digital Vision/Getty Images)

It’s Dec. 1, and that means it’s World AIDS Day. Celebrated every year since 1988, when it was established by the World Health Organization, World AIDS Day is an opportunity to raise awareness of HIV/AIDS. According to the Centers for Disease Control and Prevention, there are a few things that everyone can do to observe the day: get the facts, get tested and get involved. Let’s go through these actions one by one.

Get the Facts. Let’s review some key things about HIV/AIDS. These statistics come courtesy of Avert, an international AIDS charity:

• There are approximately 33.4 million people living with HIV/AIDS worldwide.
• 2.7 million people across the globe were newly infected with HIV in 2008.
• More than 25 million people have died of AIDS since 1981.

AIDS.gov has a great HIV/AIDS 101 section that’s worth reading in its entirety, but let me pull out a few factoids for you:

• HIV is transmitted through bodily fluids such as blood, semen and breast milk, usually via sexual contact, pregnancy and childbirth, or as a result of intravenous drug use.
• To prevent infection, you could practice abstinence from sexual contact or use a condom correctly every time you engage in sexual activities. If you use needles, don’t share them, and if you’re pregnant, talk to your doctor about ways to minimize the risk of passing HIV to the baby.

Just as important as knowing the facts is knowing some common myths; here’s the correct info from AIDS.gov again:

• HIV/AIDS is not a disease that only affects gay people — it can happen to anyone.
• You can’t get AIDS from casual contact, such as touching, sharing a glass or kissing.

This is a pretty basic overview, so if you want to do further reading, here are a few sites to check out:

• World Health Organization: HIV/AIDS
• CDC: HIV/AIDS
• UNAIDS Outlook 2010
• Act Against AIDS
• HIV Reality

Get Tested. If you live in the U.S., the CDC has a directory of HIV testing sites by zip code.

Get Involved. Want to help raise awareness in your community? AIDS.gov has a page full of tips for putting on a local event. There are also a ton of events going on today; find one near you by checking this page from the World AIDS Campaign. If you’re looking for a place to direct your volunteer time or your charitable dollars, then this database supported by Cell Science is a good place to start — it’s an international and state-by-state listing of charities and support services. And even the smallest acts of solidarity count today — UNAIDS has Facebook and Twitter applications you can use to demonstrate support.

More on HIV/AIDS from HowStuffWorks:
How AIDS Works
How AIDS Organizations Work
Why would circumcision decrease a man’s risk of contracting AIDS?