SEO is the most effective online marketing tactic for generating conversions. By solely using SEO, you can save hundreds of dollars from your advertising efforts. When doing your search engine optimization correctly, then people will find your website, blog post, salesletter, etc. with ease in search engines and you may have already got yourself a customer.
It is really important to help search engines to find your website and that is pretty easy if you know how to do it:

1) Make content readable and reachable for search engines.
2) Add content often(periodically), show to search engines that your blog is active and worth to index.
3) Organize content logically(categories, themes, sidebars)
4) Insert keywords in content, internal tex tlinks, headlines, etc.
5) Quantity of quality sites linking in to your website

Search engine friendly website is your key to get found, remember that Search engines love fresh and original content!

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* Quality inbound links to your site
* textlinks in navigation
* textlinks between pages using keywords
* HTML and XML sitemaps (search engines do not like website navigation with ajax, flash, javascript, because it is not so easy to read for them)
* Shorten URL is better than long

Great thing to use in your website is Canonical tag, because it will show to search engines that you site is original, if someone tries to copy content from it.

Some mistakes that people make and do not relize its harmful consequence:

1) Do not change your website or blog design, system with what you manage content or software you using for your website (blog). It can kill search engine visibilty
2) Always double check URLs, only one missed character in URL can cause broken links
-example.com/blog.html
-example.com/blog.htm

Link building is also important part of SEO

1) Links build a traffic to your site
2) Very important is inbound links that come from authoroty and websites that is relevant to your site.
3) Keywords in link text:
-wealthy affiliate blogyes
-Click hereNo
4) Promote your site in social networks, partner with other webmasters, syndicate with RSS feed, use social bookmarking, etc
5) Create content that is worth linking to
6) There is many many ways to build links and your imagination is your only limitation:)