Here is a basic overview of using search engine optimization (SEO) on your AdSense sites.
First off, when you write content for your site you want to focus each page on 2 or 3 keywords that you found when doing your keyword research. You will want to mix in your keywords early in your article and also at the end. Don’t worry about counting how many times you use a certain keyword, just write naturally and you will be fine.
Keyword density is largely overrated and there is no need to aim for a certain percentage. But you do need to make sure you are using your keywords in your articles.
You are also going to want to include your keywords in the title tag and your H1 tag. You can also utilize the H2 tag also. Using the title tag and H1 tag are two essentials for on-page SEO and you should ALWAYS use them. But do not just use your keywords in the title and H1 tag. Make sure to mix in some other filler words to avoid looking like you are trying to game the search engines, even if you really are 
Throughout your content make sure that you are using variations of your keywords. If I was writing an article on “golf tips” I would want to use “golfing tips”, “tips on golfing”, “golf tip” and so on. Make to use variations and plurals of your keyword through out your article.
Once you have completed several article pages on your site you will want to start utilizing in-site links. To do this simply link related articles to one another by using anchor text that is your keywords.
For example, if I have an article page about “golf tips” and another about “putting tips” I could link from the golf tips page to the putting tips page by using the anchor text “putting tips”. This will help build link reputation for your pages.
And thats all there really is to it. Just write quality, informative articles that are based around keywords that you found through your keywords research. Make sure to include your keywords in the title tags and H1 tags and also within the anchor text that link to those pages.
This may seem simple and it really is. However, on-page SEO does not have a huge effect on your search engine rankings. The majority of your work should be on getting links to your site using anchor text that matches your keywords, as this will have the greatest effect on your rankings.
