Paige Keiser at the Fox in Socks blog has an interesting post on the business of children’s illustration. http://paigekeiser.blogspot.com/2009/10/5-quick-tips-to-getting-published-in.html
Not only is it her professional advice, but the advice of other pro illustrators. Illustration is a business. Sure, the artsy part of us loves to be free and unfettered. But if someone wants to make a living in the field, they have to put in the hard work just like any other business.
The post is chocked full of practical advice. I recommend checking it out.