It’s all in the keywords you use. The most important ones are those in the title. When you match your query with the keywords in your title, the search engine will make those keyword appear in BOLD, which increase the chances of getting a click. The more bold text you have, the more relevant it is for the searcher.

Good tools to research keywords are: Google Keyword tool, Good Keywords and of course The Dowser. All these are free. if you go for professional you might want to try Keyword tracker or Keyword elite. I never tried any professional tool except a limited trial because the free tools are already good enough for article writing. Professional tools will show you also the price per click which is not so relevant for your article needs.

How to know which keywords are good for your article? See the keywords that have the most visitors. Order the program to sort the keywords by visitors. Start using the keywords with the most visitors and end with the keywords that do not have so many visitors. You see, the higher the traffic volume, the tougher competition will be but you have to fight for your right to WIN!

A good list of keywords for an article should never have less than 5 related keywords and never more than 5 negative keywords. For example if you are making an article about free software, avoid at all costs to talk about paid software in that article if you want to score high for free software and so forth. For music avoid talking about movies and so forth.

Keywords that have millions of searches per month are the most profitable markets. Again, why are keywords so important? Because 97% of the people (according to most sites) that want to know something or look up something use a search engine. This is why. Imagine having access to 97% of all the world’s population (at least the digital world).

Of course the secret to rank high on search engines is the biggest secret of all and SEO can give you only some tips because the algorithm changes every week (source: official Google blog).

How many articles should you have? No limit.