How to build up a social community membership from scratch?

One of the best and most popular script used is Vbulletin. Most of the reputable forums are powered by Vbulletin. The second recommendation I'd have is phpBB. It is absolutely free and open sourced versus Vbulletin which is licence based. I have used both and had no problems with either of them. If you can fork out some money I'd suggest going with Vbulletin. Here is a list of the biggest internet forums http://en.wikipedia.org/wiki/List_of_Internet_forums. You can see most of them are powered by Vbulletin and the second most popular script is phpBB. Regarding fresh look you can simply hire someone or buy a Template.

Not necessarily. What's key is to build relationships with the organizations that work most closely with the munis and local leaders. Often times the money comes from them (i.e NGOs, local companies, social ent orgs). In some cases software can be piloted at low or no cost with muni leaders and from there, government sees value and invests accordingly. Where will you be working? Of course every region and location is different but building relationships with organizations that work globally and know how to tap into the local groups is a great first step. Happy to chat further if I can be of help.

When I built my first company, I targeted a niche and was able to corner it. Is attribute the success of the company to a few key factors: helpfulness, consistently excellent service, and high relevance. The best way to get the support of a niche is to be truly useful to that niche. Where do they hang out online? Be there, and help everyone you can with no expectations. When it makes sense, link back to relevant resources to give them the option to research more deeply. Keep a blog full of helpful information — this helps the resources you link to when helping more useful to you, because they're yours. And — most importantly — make damn sure the product or service is filling a gap in the niche. All your efforts are for nothing if what your selling isn't wanted or needed. Then you simply have to make sure you're treating every customer like a celebrity endorser. Their word will make or break you, so make sure every client is your most important client and that they finish the project ready to tell everyone how great you are. "Pretty good" won't corner a niche; "fucking awesome" will. If you'd like to talk strategy and/or marketing, hit me up. I'd really enjoy working with you on a project like this. :) Good luck!

Social media is a good way to spread the word, but first you need to make sure you're delivering solid content and that search engines see you as an authority. The majority of new traffic to a site comes from Google and Bing. Sign up for Google Webmaster and from there you'll be able to see if you're getting indexed and what keywords people are using to find your blog. You may be surprised to find that you're not attracting the audience you think you're attracting. Good and consistent content is key.

I imagine a lot of it happens in private FB groups already. I'm a member of Dynamite Circle, which is a private community of location independent entrepreneurs http://www.tropicalmba.com/innercircle/