It's always a smart idea to have a plan of action for everything you do in business including forum marketing. You can reach many of your goals, but you need to know what they are and what forums can give you. Marketers who succeed do so because they do business in this fashion. First, they learn as much as possible about different marketing strategies. Then they take this information and find the best way to use it.
Most forum members act according to their personality. Some are more aggressive and outspoken and others are shy and reserved. So, unless you are very good at turning people off with your personality, then act the way that you always do. If you're more reserved and unsure, then just observe the forum until you become comfortable enough to contribute. This behavior is called lurking and lots of people do it all the time. It can feel a little daunting to make your first post, and it's a lot like being in a new city or town and going to a new school. Once you settle into it, then simply start replying in threads and always be courteous and offer value. There are several things that you need to consider when you go to a forum your very first time. Looking around is essential for deciding on whether or not this forum is for you. When you are doing forum postings for marketing purposes, it really matters. Consider the fact that most forum owners are not very fond of IMers in general. Should you join a forum where the owner cannot stand IMers, online marketing on that forum simply won't occur. All you have to do is read the forum rules to understand what is permissible. The conspicuous absence of signatures or links in them informative post will alert you to that, as well. The vast majority of forums, even if they allow signatures, don't allow you to directly market to the community anyway. To prevent people from overrunning their forum with ads (like a giant cyber billboard), this is typically why it is not allowed.
Don't even think about networking on a forum until you know who the 'top dog' on the forum is, so to speak. You'll typically find there's really a handful of people who have this potential. The membership numbers will also influence this. Forums that have a lot of members and a long history will have more people with influence. So it just depends on the particular forum, and with some forums unfortunately it can be a moderator who has this strong influence. It's usually easy to recognize the people who are 'leaders' on the forum as they are the ones others are trying to get the attention of. These are the people you want to work to build a relationship with.
You can work a lot of forums and still only devote about five hours click now a week to the effort and, bring in a ton of profit from forum marketing. It doesn't get much higher in value than that when it comes to marketing. But just be sure you diversify your marketing so you get all you can from it and help insulate resource your business from business and web turbulence.