How to promote a new online community?

I'm new to this site (joined yesterday). I am a web developer and I am in the process of creating a new online commuinty to cater for a particular niche market. Joining the community will be free. I don't have any products to sell at the moment*

There is no one in the community yet, so there is little information - apart from what I post myself. Obviously, more people join the community, the more attractive it becomes: classic chicken and egg situation.

I want to know how I can:

1. Promote the site - i.e. draw traffic to the site
2. Convert visitors (get membership) for the site.

I know about SEO, Keyword analysis, article writing, blog commenting, press releases, squeeze pages, use of social media etc - but its a bit of information overload at the moment, and I need a simple list of things to be done in order to start getting traffic. Basically, I know what needs to be done (or at least I think I know what needs to be done), I just need to know the order in which the steps should be taken.

I asked for some guidance in an earlier message, but that did not receive any responses - where can I get this basic information from, in order to get started and start seeing some results? (I don't mind paying for consultation once I have seen some basic results that shows that I am going in the right direction).

*Regarding products, I could write an ebook (either for sale or as an enticement), also I could sell some web software (which requires site membership) - but it is not clear how this would fit into an overall marketing strategy.

Would like to hear from someone who has actually been through this process themselves (and succeeded).