Very time consuming especially social media network, my suggestion is to plan what exactly what your goals are and then from there plan out how long it would take to get there.
It is nice that you want to build a social site for your specific niche, but with anything you build, you want to have goals, whether it is a community of at least x members, with 5 adsense ads, x amount of traffic per month, and you want to generate income by offering front page ads for certain advertisers or members who want to promote.
You have a very good chance of making a good social site, but PLAN and make goals of your overall use of the site...Do not just make a site, which you barely have a time to work, and then build list that you won't really be involved with...You are better to figure out how you could make this a part time job or part time income or full time on both.
There are many people who start very small, and then they realize the potential and that is what I am conveying with you. And so they make plans for growth. I think you should build the plan before you even build the site. and know why you want to start a community.