Momcomm -- a great blog with tips on improving your blog, including advice on affiliate marketing (i.e. getting paid whenever someone buys a product after clicking a link on your site).
My favorite feature on her site is the weekly Blog Critiques -- there's always a lot to learn by reading her advice to other bloggers. And I've found some interesting new blogs to peruse at the same time. I don't think I've put much, if any, of her advice to work on my blog, mostly due to lack of interest in writing blog posts made me think why bother making the blog better? Content is king!
But one thing I am going to try is affiliate marketing to promote the DIY Blog Critique e-book that Momcomm has produced. I bought the e-book myself and am reading through it, possibly to improve my own blog in some ways. If you're a blogger you might consider purchasing it too. If you do, let me know what you think.