Kimberly Palmer at US News has published some nice tips on blogging based on opinions of other successful bloggers. Two points that stand out:
1. Get some traffic before you put ads in the blog – "Wait until you have 100,000 page views a month, because before that, any monetization will just make coffee money."
2. Stick to a niche but widen your focus – "Instead of picking a niche like diet tips, where there’s only so much you can write, instead pick a general way of looking at life or an area of interest that you’re passionate about."