I've found Ross Dawson's piece on Tapping the power of Social Media: 6 steps for marketers to be a very useful primer for marketing-focussed clients and colleagues who wish they knew more about this whole "social media" thing. Here's a taste:
1. Participate and play The only way to understand social media is to participate. Don’t just open Facebook and Twitter accounts. You need to play extensively with a wide variety of tools and discover how they are being used. If you think you don’t have time, think how much time you’ll have if you cannot work effectively in a world increasingly driven by social media.
The other five steps are:
  1. Discover relevant conversations
  2. Identify influencers
  3. Build a relationship with influencers
  4. Don’t make half-hearted efforts
  5. Find experienced guides
What tips or info do you refer people to when you want them to find out more about things that lie "in front of the wave"?