On-Page factors are the aspects of a given web page that influence search engine ranking(SERP's). So you must focus on On-Page SEO techniques in 2016.
Content of Page
The content of a page is what makes it worthy of a search result position. It is what the user came to see and is thus extremely important to the search engines. As such, it is important to create good content. So what is good content? From an SEO perspective, all good content has two attributes. Good content must supply a demand and must be linkable.
Good content supplies a demand:
Just like the world’s markets, information is affected by supply and demand. The best content is that which does the best job of supplying the largest demand. It might take the form of an XKCD comic that is supplying nerd jokes to a large group of technologists or it might be a Wikipedia article that explains to the world the definition of Web 2.0. It can be a video, an image, a sound, or text, but it must supply a demand in order to be considered good content.
Good content is linkable:
From an SEO perspective, there is no difference between the best and worst content on the Internet if it is not linkable. If people can’t link to it, search engines will be very unlikely to rank it, and as a result the content won’t drive traffic to the given website. Unfortunately, this happens a lot more often than one might think. A few examples of this include: AJAX-powered image slide shows, content only accessible after logging in, and content that can't be reproduced or shared. Content that doesn't supply a demand or is not linkable is bad in the eyes of the search engines—and most likely some people, too.
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Keyword Density
Including relevant keywords throughout your content is very important, as it helps search engines work out what your content is about. However, try not to excessively repeat and overuse keywords just for search engine robots. This can lead to your site being banned from search engines.
Internal Linking
People often think that the only links that count are those from other websites. While these links are important, these are not the only important links!
Placing links to your other website pages, is a great way of improving your site and used properly,internal links can be a useful weapon in your SEO arsenal. Not only does it make it much easier for your visitors to navigate around your site and find all of your content, but it also ensures that your site gets properly crawled allowing the search engines to find all of your pages. It also helps to build the relevancy of a page to relevant keywords and phrases, whilst also helping to increase theGoogle PageRank of your pages.
Now coming to 2nd part, there are some resources below which are the best places to learn about
On Page SEO.
1. Moz (previously SEOMoz)
This was one of the first websites I frequented when I started learning SEO. The open spirit of the community combined with the consistent publication of thorough educational content makes this one of the first places I send those looking to learn more about SEO.
2. SEO Book
Aaron Wall is widely considered one of the true papas of search. He’s been at it a long time.
Aaron is one of the few bloggers online whose posts I never miss. Not only does he share actionable insights on SEO, but Aaron’s writing often highlights the transcendental issues that link SEO to other aspects of the online world – and understanding the big picture is crucial to surviving online competition.
3. Search Engine Land
Search Engine Land was founded by Danny Sullivan who is perhaps the most recognized face and name in SEO. Danny is frequently on the cusp of the latest developments in search – with unprecedented contacts at the search engines and a huge network of experienced SEO’s and developers.
4. SEO Fast Start
This eBook from Dan Thies, a veteran of SEO, has been around for quite a few years now. That doesn’t mean it’s outdated – Dan updates every edition with the latest in search engine updates and tactics. Dan’s writing style is straightforward, and he offers plenty of great SEO advice for beginners as well as some tips seasoned folks might not have thought of (or just need a refresher on).
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