If you are not visible on google after alot of SEO effort; make sure that the page is not/has not been penalized by Google (you can see this by logging onto your google webmaster account).
Make sure your robots.txt aren't hiding your website from crawlers.
Make sure there aren't major errors on your website (does it validate with w3c? for both css and html?)
Verify that the keywords you were targeting aren't high competition keywords - those are going to take you working your butt off for hours everyday to rank for especially when there are domains and websites that probably have more historical value then you.
Theres alot more things you can do; infact with SEO you will never truly be finished. However the biggest thing you need is time and patience. For every action you do today, don't expect noticeable results for atleast 3-6 months.