My experience has taught me to first choose a good platform and VBulletin is one of the best IMO. You have a variety of moderations and hacks that you can add to increase your member base. It also is very SEO friendly.
Be prepared to spend atleast several hours a day at the forum. It’s a good idea to have enough people assisting you so that someone is usually always at the forum so that the members know their issues/questions will be addressed in a timely manner. I try to get staff that is from different parts of the world so that someone is always up and working at the forum. 45% of my members/visitors are international so that is important for me.
Remove all spam and ban spammers asap. Let everyone have their say as long as they are not attacking others personally. Eventually the members will build a ton of content and you don’t have to address every post because they all help each other.
At one time I had 1,000 unique hits a day, but it dropped a little around the beginning of this year.
It does not happen overnight, but it’s well worth the effort if you want to take full advantage of this industry.
Good luck! 