Personally, I have little use for forums/discussion boards and large seminars. My impression of both is the bulletin board that you see at all grocery stores in the front lobby. Pretty much impossible to find anything useful in all that clutter. It is disjointed and much of it is not relevant to your particular request.

So to make either more successful, you need to get it down into small manageable groups or on a one-to-one basis. If you have ever attended a large business seminar, you will have experienced the waste of time and money that they are until you get down into smaller work-groups and discuss specific ideas. Now you have something that has the potential to return something of value. So your challenge in moderating a forum is finding a way to get the topics broken down into smaller "work-groups" or having two individuals discuss the idea one-to-one.

Forums, discussion boards and seminars are supposed to be about improving communications and I still believe that the best way to communicate is one-to-one or in small groups. Blogs and hubs are really one-to-one so they have a greater potential for conveying a message successfully.

If you must build a forum, you must also flush all the clutter that people put into it when they get off-topic or become self-serving. For it to be useful, you must also close topics at some point and delete outdated information. Keep it small, informative, useful and timely and it might actually work.

I take part in an online game that has a forum for all the members of the team. Funny, when you want to convey something important, you revert to sending a one-to-one message or a group circular mail message since the forum just gets overused with people discussing things that should be done via private messages. If it doesn't relate to the entire group/forum/seminar it shouldn't waste the time of all the other members of the group.

How you keep people on track is the job of the moderator. Unless you keep everyone on the topic, your forum or board will end up looking like the grocery board and your "dog or cat" will stay lost. I hope you are a patient individual. You will need it.