Hi Anna, The best place to start would be to build your website out by regularly adding content. Google especially favors bigger, content rich websites. From there it's the Time:Money ratio. Do you currently have more time or money? This will affect what the best SEO strategy would be for you.
You should do the following..... Article Distribution Press Release Blog Commenting Social Network Submissions Social Bookmarking Forum Profiles Web 2.0 Profiles Do the above on a constant basis, monthly, and reap the page one benefits for all your sites and your sites' keywords. BTW, I use the combination on my clients sites and it works GREAT!
you have to make quality backlink for perticular keyword and must be unique content for your website.
optimize all the keywords. I've read an articles that say Google doesn't love websites that target only ONE keyword. what you did by targeting multiple keyword is good, your SEO should focus on all the keywords on your site.
There is an another way, integrate blog on your website and get link from unique content from it. It is very effective way for improve search engine ranking.