A little while ago I stumbled across problogger.net and became hooked. Problogger, as evident by it's name, is about professional blogging. Darren Rowse, the creator of problogger, lives in Australia and makes a good living from blogging. He doesn't say exactly how much he makes, but he wrote an article about "The house that Google bought".
http://www.problogger.net/archives/2005/03/06/look-what-blogging-bought-me/
Problogger is stuffed full of useful articles about blogging. It covers marketing, advertising, making money, writing skills, and anything else related to making a sucessful blog. The articles are well writen, and the site keeps me coming back for more. These articles give me good ideas that help keep the gears spinning in my head.
There is a section on advertising, which I am starting to experiment with. I am intrigued by the possibility of making money by maintaining my website and writing about things that are interesting to me.
Blogs are pretty easy to set up nowadays, so anyone with something to say can publish one. If you'd like more information about the business of blogging, please visit problogger.
http://www.problogger.net