First, Google wants to see your content. Make sure you have your keywords/keyword phrases in bold in the text, throughout each page.
Second, make sure that you have an up-to-date
sitemap.xml file for your site on Google Webmaster Tools. Generate a new sitemap.xml file whenever you have substantially changed the content on your website to let Google know that you have new information that Google can crawl and add to possible search results based on the new and updated content on your website. You can have many sites create a sitemap for you just use Google to search for a 'Sitemap Generator', for more information regarding sitemaps please refer to http://sitemaps.org for some great information about the sitemap protocal and other bits of information that Google can utilize to aggregate and help bring visitors to your website through positive search results. If you do not know how to upload a sitemap you should go to Webmaster Tools click 'Optimize' then click 'Sitemaps'. You will need to upload your own sitemap to your server and tell Google Webmaster Tools where your sitemap file is.
Third, in Google's Webmaster Tools you should have the service 'Fetch as Google.' This way Google is aware of major changes within your site and will more than likely recrawl your site within a week or so. Log-in to Google Webmaster Tools and go to the site you are working on then click Health > Fetch as Google. Once you have pulled up the "Fetch as Google" page you should click on the button which says 'Fetch' as the URL is, if you want to fetch just one particular page as Google you can enter that specific page after the http://yoursiteurl.com/ automatic prefix for your particular domain that you have selected.
Fourth, focus your content around your keywords and keyword phrases and make sure to bold your keywords and keyphrases; also, make use of bulleted listing with your keywords and keyword phrases. This goes a long way with Google. Google wants to know that they are providing their searchers with the best, most relevant, and accurate information based on their search query. Content is King, don't forget that. Creating content on a regular basis serves to expand your page and will make your page more relevant in SERPs.
Fifth, everything takes time. Focus on putting more content on your site which is relevant to your keywords or the theme of the site with regards to content. Google indexes oodles of pages a day and crawls sites all the time but things can get backed up and it can take a while for Google to index your site and allow you to become earning higher spots on specific searches. So have patience!
Sixth, Google does not promise that your site will be indexed at all but by using the above methods you should be able to have your site crawled/re-crawled by Google and other search engines. This is where the robots.txt file can come into play in a bad way. You should make sure that your robots.txt file is not blocking search engines from indexing your site. Make sure that you have not turned off search engine indexing for your entire website by accident. I have seen this countless times.
Seventh, keep working on refining your keywords and keyword phrases. Use AdWords to determine some of the better suggested keywords and keyphrases for your website. AdWords is a pay-per-click system but you can gather good, resourceful data about keywords and variations thereof which you should focus on through AdWord's suggestions.
Eighth, to find out what some of the most influential (to your website) search terms are to get new arriving visitors on your site - you can go to the Webmasters Tools and click 'Optimization' and then click on 'Content Keywords' and a list of commonly used keywords to access your site appears. To get a good look at which keywords are most successful in bringing users to your website this is a great tool! Use this as a guideline and focus on the top portions of these keywords, these should be something similar to the content offered on your page.
Ninth, backlinks, try to acquire as many backlinks from all sorts of other people's websites with related, informative pages on your targeted topics and even some unrelated websites. Add your website to your profiles on different online accounts, especially on Bulletin Board Systems. A backlink is where another page (not on your server) links to your page. You gain a better chance of Google displaying your information if you have quality backlinks to your website from quality, reputable websites which offer some of the same kind of content as you do. The higher the PageRank of the page that links to your website, the better your chances are of increasing relevance to Google and this will increase your PageRank as you have more and more dedicated links from other website's to yours. If you have a highly ranked backlink your page will begin to show up higher and higher in Search Engine Results Pages.
Ten, by executing these steps you can really change the way that a search engine views your site through keywords, content, relevancy to user search, and having Patience.
For further information concerning the Google Content guidelines please review: http://support.google.com/webmasters/bin/topic.py?hl=en&topic=2371375 , which you should follow or you could be banned from Google's services for web masters. Best of Luck!