Kevin Wheeler has a good article on the ERE website today titled What Makes a Blog Work? There is excellent information within the article if you are looking to start your own blog (something I strongly encourage).
Here is a juicy tidbit:
A survey published last fall by Forrester’s Charlene Li indicates that “24% of Gen Yers read blogs, which is twice as often as the 12% of Gen Xers (ages 27-40) and three times the 7% of Young Boomers (ages 41-50) that read blogs.”
Those types of stats are always fascinating to me. After that, Wheeler provides 4 tips that all have merit:
Short and Fun
Personal
Story-based
Authenticity
He expounds on each point with insight. I recommend you read the entire thing.