I have few keywords which are doing well for others with niche tht i have. can i add those keywords to my site?is this correct way of adding keywords to your site?or is their any other way to get keywords for my site?plz help very urgent.
keywords serve a single purpose... to match the Searcher with the Content. So you add the appropriate words that match the two and you'll be fine. Sounds like you have not considered the end user.
Placing the targeted kyeword phrase on a page is called "On-Page" SEO and there is a basic 20 areas that you will need to consider. I'm not going to list the all here, but if you go to http://www.catanich.com/search-engine-optimization.asp you will find a list with examples that may help you.