A great overview of Google+ from the folks at Hammock
Hammock Labs has written a nice overview of Google+, intended for a non-technical audience.
What is Google+? (And why that’s not the important question)
What can you do with Google+?
Who can use Google+?
How Google+ is like (and not like) Facebook
How Google+ is like (and not like) Twitter
How Google+ is like (and not like) LinkedIn
How will people have enough time to use all these social networking things?
How will I (or my company) have enough time to use all these social networking things?
The coolest “new, new” things about Google+
The early “missing” things about Google+
Predictions for Google+
Short-term recommendations for businesses and the people who run them
Conclusion: Our most confident prediction
I agree with the bulk of what they have to say, so it's a good place to start for someone that doesn't understand what it's about. Check it out for yourself and see what you think.