Please help me with keyword for this site. What i have to do, Use multiple keywords or use one by one keyword for search engine top spot?
Use multiple to get rank your website in top 10 in Google. If you use one keyword at a time so you won't be able target other keywords in SE.
You need a good mixture of long tail keywords and short. Start with 3 - 4 keywords and then expand on these.
use Google Adword to choose some suitable keywords for your site. Do not choose neither the one which much too people search for nor too less people search for.
you can use one primary and 2-3 secondary keywords with low competition per page. mainly focus on the high volume keyword link building but occasionally do some link building for the low volume keywords as well. google finds it suspicious if you only have one kw and point all the links to your site using only a single anchor text.