Some people (really smart people) blog because they are a wealth of wisdom and insight. To be sure, that does not describe me. I blog because the self-imposed daily demand stretches me to learn new things.
Today, Tim Challies writes on this topic. In part he says:
I have found blogging a wonderful way of ensuring that I continue to grow and mature as a Christian. It has forced me to dedicate myself to learning and has really become one of my spiritual disciplines, as strange as that may sound. It has caused me to have to grow up. I know of many bloggers who would say the same.
Yes, I would say the same thing. I frequently realize I have nothing more to say, so I pick up another book and learn something new. If you’re kicking around the idea of a blog I would advise you (1) don’t make that decision limited upon what you already know but upon your level of discipline, and (2) read carefully all of Tim’s advice here.
Tony Reinke 
That steak pic gives my stomach fits!
Thanks for the link; great advice! I’m new to the blogosphere and your timing for posting this couldn’t have been better. Tim gave me some good things to think through. By the way, thanks for your example of how helpful and edifying a blog can be. Your site, along with a healthy dose of encouragement from my wife (a veteran blogger), encouraged me to start my own.
A suggestion for lazy people like me, find a friend and blog together.