That is a good start but it is important to not just jump into these channels without thinking about the audience - this checklist may sound good for SEO but it is may not be the best for your potential audience.
Explore their communities - for example, if you were targetting SEOs then you would hang out on SEOmoz, share content on inbound.org, comment on searchengineland.com, tweet the industry leaders on Twitter etc. By joining your niche communities you will build up connections and awareness which will help you gain links at a later date.
Before you publish content I would suggest joining in the conversation. That way, when you begin publishing your content you will have a basic following to be able to market to.
There is no secret but to be honest most people on here are very open and willing to share their expertise. I hope this question gains more of a discussion!
What kind of industry is your content targeting? Or is this a general checklist that can be applied to any industry?