First of all, avoid posting when you don't know what you are talking about. That will make you look stupid. Nobody knows the answer to everything. If you are unsure what the proper answer to a question is, take a pass. Spend your time answering posts where you can really offer value. Don't post just for the sake of inflating your post count or showing your signature files. Pick your battles wisely.
Some questions are just too difficult to understand. Or just plain weird. If that's the case but you still suspect you can offer value, ask for clarifications. Ask for more details or ask questions of your own so you understand exactly what the question being asked is. When the question is clarified, post with your answer.
If you don't know the answer, simply don't post. You don't really have to follow up on your initial post. The forum advantage is that you can really think of your answer. Or, you can just avoid answering altogether.
If you are not quite sure of what the answer to the question is (but you kinda know), you can make a "short and mysterious" post letting it be implied that you do
know what you are talking about.
If you know that you spell poorly in general, make sure you spell check your posts before you actually click the "Post" button. I used to paste my post in Microsoft Word, have it spell checked and then post on the forum. But now I use Mozilla Firefox and there's a built-in spell checker that underlines with a red line every word that appears to be spelt incorrectly. If you right click on that word, you will get some recommendations of what the proper spelling is.
Also, you can preview your post before making it. If you are not sure if your post will come out looking ok, click the button that says "preview" instead of "post". Then, you can safely make any modifications you want before you actually post.
Or, even if you do make an error somewhere, you can go back and edit your post. All forums that respect themselves will have an "edit" icon on your post so you can click it and edit your post. Note that you can only do that when you are logged in with your username - so the forum can recognise you. Of course, you can only edit your own posts - and not those of other forum members.
And of course, nothing stops you from creating your own threads. That way, your post will get more eyeballs since it will be the top post and will not be buried within other replies. I admit that I don't usually do this because I prefer giving answers to posts and branding myself as an expert. If you are trying to do this, you can't start making post after post asking "silly" questions.
But you can definitely start challenging threads. Especially if you know that a subject polarizes an audience, by all means go for it. For example, many people hate popups while others hate pop up blockers. In this case, you could post something along the lines of:
"Hi guys,
I know that some people hate popups. But I also know that they still work and they can add to your bottom line. Which camp do you belong in? Do you love popups or hate
them?"
You can get quite the heated debate going there. If you have a popup blocker or a popup generator in your signature file, even better :-)
Or:
"Hi guys,
Do you prefer paying for your advertising and getting fast results? Or do you prefer free promotion methods that may take longer to see results from?Post your thoughts!"
Again, the two camps of free and paid advertising can have a very interesting discussion. If you promote a Google Adwords Guide or an SEO Software in your sig (or both), you can do very well. Make sure you post again after other people post. You want your posts and sig file to be seen throughout that entire thread.
In general, try to start threads that are very related to the product(s) you promote in your signature files. I can tell you that forum threads can rank at the very top of Google, especially when the term is a product name that is about to be released.
Product names have very little competition (plus, people who search for them are great buyers). Let's say that a new ebook called "The Super Ebook" is about to be released.
If someone starts a thread around it, make whatever possible to post as many times in there as possible. Even if you haven't seen the product yet and you aren't promoting it yet. As the name of the product will be repeated throughout the thread, that thread can rank very high on the search engines.
When the product does go live, many people will start searching for it online. Next thing you know, they see the forum thread, they visit it and they start reading
the posts.
At that point, it would be wise for you to read the product, set up a landing page for it offering a review and a bonus for people to buy through your link and, of course, add a link in your signature file saying something like:
"The Super Ebook Review". All your posts will now have a link to your review of the new product. And of course, nothing stops you from posting again in that thread. People usually read the very last post on a thread. You can even be direct and say something like: "I just bought The Super Ebook. Check out my review in my sig file".
If you see a forum thread on one forum that has generated a lot of interest in a forum, you can just start an almost identical thread on another forum in your market. You should get some solid action going.
If you have posted an answer and, several days later, you see the same question being asked again, you can just say something like: "See my reply in this thread as well." Or, you can just copy and paste that answer in the new thread.
Another creative idea
You can visit a forum (in any niche) and then click the "members" link. This will give you a list of all the members in the forum. You can usually sort that list by name, number of posts, etc. If you sort by number of posts, you can find the members that are really active on the board. Perhaps you can select a few of those members and "cut a deal" with them.
For example, you can tell them that you would like to "rent" their signature file space for the next 30 days for X amount of money. If they say yes, you now use all the techniques and you set up their signature file so that it makes YOU money.
You'll get many backlings to your offers instantly. Also, since these members post a lot, your offers will continue getting exposure. Plus, members who search for older posts will almost be sure to find some of the older posts of the members who now have YOUR signature file - and follow those links back to your website.
If you want to find forums in your market, just type "market forum" in Google, Yahoo and MSN. For example: "internet marketing forum." It's simple.
Here are some resources to help you find more forums
http://www.big-boards.com
http://www.forumzilla.com
http://www.board123.com/forum_directory.php
http://www.foruma-z.com/directory.php