I just finished an excellent article that covers 25, no-scam ways to make money with a free WordPress blog from www.WordPress.org.
You can read the complete article here. I used to publish a book titled Make Money Blogging From Home. (Now out-of-print), This article covers all of the topics in my book albeit in a shorter form. I highly recommend anyone who blogs to read this book.
I also publish another book related to blogging titled How to Make Money With The Amazon Affiliate Program.