1. “Social media” and “social networks” are not synonymous terms. Social media is the umbrella term for a range of online content that includes blogs, wikis, photo sharing services, social bookmarking sites, and social networks, such as Facebook and MySpace.

2. It's important to spend some time thinking about your settings on the social networks to which you belong, and to revisit those options regularly.

3. It's a good idea to use caution when meeting people on any social network. The safest social networking strategy is this: Network only with people you know in the real world.

4. A good rule of thumb to follow when you're considering the personal information options of any social network: Start by including things you wouldn't mind telling someone you just met at a party.

5. The blogosphere is the vast information network made up of the entire world's blogs, along with reader comments and any links or connections.

6. Tens of millions of people, from average joes to professional journalists and marketing gurus, are blogging every day.

7. Two issues that should concern you as a blogger are publishing statements that could be false or cause harm to someone's reputation, and violation of intellectual property laws by improperly linking to information, quoting from articles and other blogs, and/or using someone else's creative works.

8. Twitter is the world's most popular microblog, and its users generate about 600 tweets per second. But it's not the only microblogging service. Tumblr, Plurk, Squeelr, Beeing, Jaiku, and Indenti.ca are other examples.

9. A tag is a key word attached to a piece of web content, such as an online article, a blog posting, a digital photo, a video clip, or a website. Techies call it metadata, or data about data.

10. Virtually any crackpot with a bone to pick can badmouth your business online on one of the opinion-sharing sites. As long as it's not libelous, everybody's opinion is welcome. For this reason if for no other, companies can't afford to ignore social media.