We are just about to launch an online marketplace with a focus on waterfront lifestyle living.
Shaun Nestor has a great outline of things, but just to add a couple more points.
Your content that you build should be targeted at keywords to boost organic search. You can research competitors to find out what keywords they're using and find opportunities to get ranked quicker.
Be sure the Keywords you're targeting are valuable to YOUR BUSINESS. Some people make the mistake of trying to rank for keywords with large daily results, but you want to attract well qualified visitors that will convert. This may mean lower search volumes but better monetization of your visitors.
Lastly, be sure that your outreach plan includes things that will help build quality links like guest posting on popular blogs.
Content and SEO go hand in hand, keep that in mind when you do your research and build your personas.