you need to know if the keyword that you're going to use will deliver more results.. you have to do some research.. make a list of all the keyword that you can use in your site.. after that use a keyword selector tool like OVERTURE and WORDTRACKER..using those tools will help you know which keyword are search more often..
I agree to gHing.. you can also use this tool http://www.digitalpoint.com/tools/suggestion/ I have posted this tool to another thread awhile ago and i am recommending this tool again because this is the tool that I always used when choosing the best keywords to gain traffic and to improve my SERP.
today.... by all means "find" some backlinks that coresponds with your keyword. tomorrow.. who knows.
after you got a keyword for your page. then build more links from other websites and point to your page with your keyword in anchor. but don't spam.
get links using the kew word form the other sites. and write SEO article /content for your site. terget keyword and make the density.