No offense but this is always something that cracks me up because most non- SEO types think of SEO as an afterthought. perhaps you did not intend to phrase it that way but that is the way it sounds. For truly effective SEO, you should be consulting with someone from the outset as far as site structure and a myriad of other things to do with SEO, before, not after.

Anyway with regards to your question. Lots of hard work on forums, maybe a press release, lots of social media sites and social bookmarking etc - there is no silver bullet... diversify your efforts and take a multi-pronged approach is my suggestion.