Placing the ads properly is great. However, it does nothing if you have no traffic. Work on quality content that will attract visitors and make sure the content is original. You need to promote the site by getting quality related niche back links pointed to your site. Update as often as possible and build a loyal following. Once you do this, you can tweak the placement of the ads all you want but until you have good traffic, ads mean nothing.
Yes, that placement of ads really works. Great chances that user will click the ads when you place it in a keyword-rich part of your blog/site.
Yes, good suggestion. Good content + Good SEO -> Good Traffic -> May be more clicks. I'll try to write blog everyday. Hope it will bring me more visitors.