In the short term start an Adwords campaign. While this is going on build loads of relevant, high quality, backlinks and make sure your site has great original content. Add some quality linkbait to the site as well then wait 12 months and you will be doing well on google.
try to submit your site to as many directories as you can . when you will have a page rank of 6 then you don't need adwords anymore and don't forget to create pages with lot of content google loves the content in this way you can promote your site for free