You can find as many forums as you want that are relevant to your niche. All that's needed now is to find the forums that get the lion's share of the traffic in your niche so you can put your plan into motion. This is a plan you can put into place fairly quickly, no matter what you've been led to believe in the past. With all good things, however, time and care are required in order to get a maximum ROI. Only you can decide the best route to follow for your business.
Many many will act the way that they normally act when they are in forums. There will be many who will be either introverted or extroverted. So, just act normally, unless you are very aggressive and obnoxious. If you are the shy type, you don't have to start contributing right away. This is a common activity called lurking. Creating a new post may intimidate you in the very beginning. Just begin by answer other threads and being helpful. After arriving at a new forum, you need to surf around to check it out for a couple of reasons. Deciding to join is fine, but you need to know a few things before this happens. When you are doing forum postings for marketing purposes, it really matters. If you want to market your products, the forum owners may not feel too kindly about your intentions. If your goal is to do this, but the owner won't allow you, it's not going to happen. Simply read the forum rules. These will tell you what you can and can't do quickly and easily. The absence of links, and signatures, at the bottoms of posts is a clear sign online marketing is not allowed. You typically can't do direct advertising in any forum. If they did, then the entire place would be one giant billboard and people would not like it.
It doesn't take long to see that some people always seem to be coming up with new ideas and beginning new threads. I don't really care about it, but it creates impressions check out here in other people that are not always positive. Don't use all your great thread topic ideas at once. Spread them out over time.
Don't neglect the other threads on the board. Human nature is the rule of the day when it comes to using forums. But on the other hand, you cannot respond or live your life according to what everybody else thinks you should do. These are the gray areas in forum marketing you'll experience. The best approach is to share your knowledge in as many ways as possible.
It's very easy to develop an addiction to hanging out in forums. Just remember why you're there. Don't lose sight of the value your time has and where it would be wisest to invest it. That's what you have to do if you want to make the most of your time.