Have in-depth knowledge in your niche? Package it up into an ebook and sell it on your blog. I'd generally advise against selling it (at least exclusively) on Amazon or Kobo, as you'll probably be able to charge much less. If you've already built up a solid audience, you can probably change anywhere from $5 for a very short one, all the way up to $39+.
Advertising is easy to start, making it a popular income stream for many bloggers. However, it’s not nearly as lucrative as it once was and it requires a lot of traffic to be truly profitable. Also, it runs the risk of frustrating your readers (ever been on a site only to be assaulted by the ads?) and making your site look cheap and unsophisticated. Therefore, it’s not a top recommendation of mine.

Thanks so much Jon. I have been struggling to ‘get off the ground’ and am devouring your insight and knowledge. You offer such invaluable and proven information and are totally inspiring. I know I CAN DO THIS and will continue to soak up your posts as they come through. I won’t wast too much time now on Facebook and Twitter which I’ve been trying to get my head around. You see I am very new to everything!
Make it easy for readers to browse – If you want more pageviews, you should make it as easy as possible for readers to read your other blog posts. You will want to make it easy for readers to find your blog homepage, categories, tags, search bar, and so on. Also, I recommend including links in every single one of your blog posts, so readers can easily find related topics.