1.    The very first step in SEO is Research the keywords. Decide what search queries you want to show up for. Do some deep research on how many people are actually searching for your site. There are several tools available from Google, Overture, Word Tracker and third party software developers that can make the keyword research process easier.
2.    Try to think outside of the box. Don’t just focus on your primary or main keywords. For example, if you are a builder in a particular area then don’t just optimize your web site for “real estate.” Try to optimize your website for Flat, House etc. You would be amazed to see that (use Google Analytics or any other third party software) how many unique visitors will come through to your site when “outside of the box” thinking occurs.
3.    Content is the King. Search Engines and End Users loves to get fresh content. Think about what your target market needs to accomplish their goals, and then put it on your site so that they can find it. If you want to be relevant for specific keywords, than you need superior or at least highly competitive content. Write about 250-300 words of copy for each keyword and plant it on your site each day. On average, one can target between 3-5 like keyword phrases per page. Make it as natural as possible and the Search Engines will reward you with a first-page ranking.
4.    Now it’s time for Title and Meta Description. Make sure that all the pages of the site have unique  titles and descriptions. If your site is using the same tags for all the pages, you are not helping search engines figure out the subject or relevance of your individual pages.
5.    Keep the structure, navigation and URL structure of your site simple enough for search engines to follow. Remember that search engines cannot read your navigation / link  if it’s developed/written in Flash or Java Script. So always try to use text for hyperlink/navigation.

Hope this article gives you a very clear idea of SEO.
SEO Specialist