Suffering from social media overload? Join the club. It seems as if every week as there’s another site everyone’s buzzing about that you must be on and another network you’re getting invitations to join. James Andrews, a managing partner of the Atlanta-based social media communications company Everywhere, blogs and tweets as the “Key Influencer” while helping companies develop social media strategies. And he says you can have an effective social media presence by being in just a few places. We asked Andrews to boil it down for you to the absolute musts.

Twitter (For Businesses and Professionals)

“It’s a wonderful place for people to learn more about what’s inside your head. Twitter is important because of the ability to get news fast from the people you want to hear from.” Andrews also points out that if your business isn’t on Facebook and Twitter, savvy consumers will make assumptions about it.

Facebook (For Businesses)

For businesses, Andrews suggests leveraging the sheer number of users on Facebook by engaging them though a fan page or Facebook groups. “There are 600 million people on Facebook, and they now are yearning and searching for more. Your brand could be that thing that satiates their appetite.”

YouTube (For Businesses)

“Video is becoming just as powerful as text, and YouTube is the second largest search engine behind Google. Especially if you have a product, it’s a great place to do unveilings.” Andrews says how-to videos do especially well on YouTube, so boost business by helping people learn to use your product.

Wikipedia (For Professionals)

Andrews calls Wikipedia the “attic” of social media because many people don’t think about how they are or aren’t represented there. “Wikipedia is highly indexable; it’s a great place to put your bio up to allow people to see who you are. If you’re a public person, you definitely want to pay attention to it.”

LinkedIn (For Professionals)

“For a professional, LinkedIn is critical. LinkedIn’s a great place to be found by headhunters but also to connect with other professionals.” Andrews suggests LinkedIn groups for engaging with like-minded people and also linking your profile to your Twitter account for greater exposure.

Read more social media dos and don’ts:

• Don’t let Facebook get you fired
• 5 Twitter mistakes you should NEVER make
• 10 Ning networks you need to know