I myself run six blogs, five of which are updated daily and one of which is updated whenever I can. Check them out at
http://www.rochardsbunnyranch.com/blog/trades.
I do this part time after hours on my own time. At the beginning of the month I write in all of them for the next month, and once that is all caught up then I spend time on improving them. Most of my blogs are rather new so right now I'm concentrating on getting traffic to them.
Currently the five daily blogs are updated until the end of the year.
It's not hard staying motivated because I'm making some decent money from the blogs....