How to choose a correct keyword???

you can learn from free video from buyers keywords generator...it's free and full of information about finding keywords.

 

perfect keywords choose by web page content.

 

Try the Google Keyword tool.

 

Use Google keyword tool and select those keyword which have high search volume (high global search volume - if ur audience is globally or select high local search volume if ur audience is in particular location) with comparatively lower competition. (there should be a balance between high search volume & low competition)

 

Wordtracker is a better tool. It's easier to choose the best keywords. It gives short and long tail keywords.