I'd identify blogs that cover the sort of business your startup involves. Make an interesting write-up about the ideas behind the startup, perhaps bios on the interesting people involved and the talents they bring together, any info about the new venture you feel might be considered interesting and newsworthy by others, and that doesn't disclose trade secrets. Email your write-up to each blogger with a polite cover letter asking them if they would be interested in doing an article on your business, and offering to answer any questions they might have. Tell them that you will do your best to provide them any additional information or photos they may need for their blog.

I know there are services that will professionally handle this sort of thing as part of promoting a startup. If you have the funds, search the Web, pick the best you can afford, and let them do it. If that's not in the budget, search for articles and blogs talking about how it is best done. Good luck with your business venture.