I started a BBS focused on my town 8 months ago. It's growing slowly but surely. Here's a few things I've picked up. Some are applicable to all sites. Also, while many may be obvious to you, they weren't to me.
Ask yourself, what do you bring to the table?
Reality check time. If your area is already served by one or more well-entrenched boards, you should think long and hard about proceeding. Basically, what will you offer that your competitors don't?
The main problem with local boards is you're drawing from a very small segment: current and interested former residents who are willing and able to make a local BBS part of their routine. Basically, show up regularly, read, and post. I don't think that's even one percent of the population. Realistically, a lof of the people you'd most like to have as members have busy lives and do most of their interaction either on the phone or face-to-face or both. Politicians will show up eventually, though, if they see voters to be swayed or untruths to be corrected.
You need a core group or your board will look, and eventually be, dead. There are two places to find them: at your competitors, or out on the street, so to speak. The vast majority of them are already at your competitor. Concentrate on the them. If you can find a niche and bring in people who aren't using any board, more power to you.
Don't assume that if you build it, they will come
Let's say you've proceeded and built a good looking, functional board with a lot of content and user-friendly policies. Meanwhile, your competitor's software dates from the Clinton administration and he lies awake at night thinking of ways to antagonize users.
I hate to tell you this, but unless you can get a core right away you will need to persevere for many months. No one likes a little-used board, no matter how good it is. My former employer's marketing guy tried to help me get a buzz at startup, but we couldn't.
BTW, the reason your competitor runs his board like he does is because he can. In the years he's had his board, a bunch of would-be challengers have come and gone, and he figures you will, too. So do his users. You will get even with him by spamming his users, especially the newest ones who will be most receptive to your pitch.
KISS (Keep it simple, stupid)
Don't look at popular topics of conversation and build your board with a place for everything and everything in its place. The board will look big and barren. Add new forums as activity warrants.
Appearance is almost everything
The stock style is probably functional but boring. Replace it as quickly as you can with something attractive.
Flatter people without being an a$$-kisser
I wrote about the good cause one of our local go-getters had taken up. She found my site from a vanity search, started posting regularly, and is now my moderator.
To thine own self . . . lie
I featured a site called antimagnet.com on my portal because I supported its message. Another TAZ user politely asked me why, and did everyone in town support it? The reason I had it up is I'm an idiot. I took it down not long after, and also started noticing the stupid magnets on local cars. No sense antagonizing potential users while you're trying to build a site. Antagonize them later.
This is pretty obvious, but you really should spend time on your site as both a guest and registered user. I keep finding broken things, and every time I add a hack or style I'm sure to find more. Make sure everything works and that the site is easy to navigate.
Put on Ted S's thing to encourage people to become members. It hasn't been the goldmine I'd hoped, but it does work. Also, see if there is a hack that posts in the Introduction forum when someone signs up. You do have an Introduction forum, right?
Print up flyers. Be careful where you put them or risk getting fined. I've hit a bunch of bus stops. If you have collaborators who can get flyers on bulletin boards in their buildings, stores, or developments, by all means do.
Try to enlist well-connected people without being a pest. I gave one a bunch of flyers and she left them on the table at a political function where they were all quickly snatched up.
Evaluate newspaper advertising in terms of bang for the buck (or pound or whatever). They got word out about my site, but were ineffective at getting members. The ad was fairly expensive. I'm still glad I did it, because otherwise I'd be wondering if it would work.
It's important that what you do looks professional, even if it wasn't done by a professional. A coworker did my logo and flyers and I paid him in O'Doulls. I've received continual compliments on both.
Don't kill yourself duplicating information that can be easily linked to. Rather than listing the library's hours, just link to the library's website. The one really useful thing you can do is keep your calendar populated. I collect meeting and event dates and agendas and consolidate them in the calendar where the entire month is then available at a glance. This really is a killer app and my competitor wasted no time copying it. Oh, and make sure your calendar remains accurate. My town has a bad habit of changing dates and starting times with little notice.
Any criticism of the board, constructive or otherwise, should be handled in private. Don't let it hang out in public, because while your thick skin may handle it, your other users won't be impressed. It ended up giving me an opportunity to test the miserable users hack. Works really well.
A well-run local board is an information clearinghouse, social gathering point, and significant resource for current, former, and prospective residents. Oh, and a source of pride for its owner. Learn from other admins' experience and create one of your own.