Ozzu has done well, But in fairness a lot of the time successful forums come about by sheer luck. There are things you can do to increase your chances of becoming a lucky forum though. You, as the administrator, should have a great understanding of the subject of your forum (Or at least know more than the people who visit.). So as ozzu is a webmaster/coding forum, bigwebmaster had knowledge in this field, So is able to provide answers to most, if not all of the initial questions asked.
Secondly, having a bunch of friends who can post will help. People are more likely to participate if the forum appears active. If this means setting up 200 names and posting under them names yourself and spending a weekend having conversations with yourself, then so be it. You have to make your forum look active.
The third thing i do is start threads answering some of the most commonly asked questions, This way you will be more likely to be found in search engines.
You can find out what are the most commonly asked questions by looking at related sites and seeing what threads get the most views.
The fourth thing is to welcome people.
The first thing people usually do is set up a "rules" thread telling people what they can't do. Rules are needed on a forum, but you don't want to look like a little hitler when you are trying to get people to join.
Change "register" to "join us".
Set up a forum for people to post when they first visit, and make sure you, as the admin, reply to these threads, appear interested in your members.
You could have rewards for people who post a lot.
Simple things like changing the colour of their user name when they reach different amounts of posts, Or add peoples sites to a banner rotation when they reach 500 posts (if its a webmaster forum).
GodBeGone - Atheist Blog