The best way to market your website is to start at your website. What I mean by this is content.
Writing articles and tutorials as already mentioned is a great way to get visitors to your website. Being able to write an informative article is not an easy task, you have to be able to include research (facts and figures) and focus on what you are trying to say.
The hardest decision you will have to make when writing an article will be what to write it on, it has to be something unique, or alternatively an article can be on something plenty people have wrote about but with a unique point of view.
Once you have finished your articles, submit them to article websites and if you article is unique and catches the users attention, they will most likely visit your website.
Another way to promote your website is through a partnership, share an interest with an admin of another forum, or several other forums.
Try to find a common link which in your case is pretty obvious; computers. If you can find another forum that wants to expand on what they offer their members, without actually creating any more forums, then they might well advertise your forum free of charge; in exchange they will probably ask you to do the same. A good example of this would be a forum about coding partnering up with a forum full of web designers.
One possible partnership with your forum could be a gamers forum, gamers are notoriously fond of modding and hardware so they would probably take an interest in your forum.
Depending on how much knowledge you have of the subjects on your forum; you could submit a few news pieces to several computer magazines. Now it is unlikely the magazines you find in your local store will accept and print your article, however, hardware e-zines might well take what you've said on board and quote you in an upcomming newsletter.
Or alternatively you could start an e-zine yourself, post around on forums such as NP and WHT looking for writers and let members of your forum contribute to what goes in them. Once they are complete post them around, show people what you have come up with!
Public speaking is always an option, I was once asked to talk to my class in college about web design. Ok, yes, it's only one class how far can the information go? Well you'd be suprised. There are often lots of positions open on computer courses where they want speakers to come in and talk about their experiences, which could again generate more traffic.
Links in your signature has already been mentioned, but why stop with links just on forums? Put them on the end of your emails to and email people in your address book. However, do not go over the top and email people who you don't know and probably don't want your email address. Unwanted emails will look bad for you and your website.
Finally, one thing your site seems to be lacking is Reviews!!! Reviews are a sure way to gather visitors to your website. You won't like what I have to say next but I'll say it anyway, change your website. By this I don't mean change the design (I love the design) but have a frontpage with collected information such as reviews and your newsletter but make it clear that you have a forum as well.
Websites which have front pages listing reviews, special offers and articles (cnet.com) for example, tend to be more popular than forums where the visitor has to search around to find what she/he is looking for.
Getting back on track to what I was previously talking about; think about how many times you look something up on the internet e.g. "Razer Copperhead Review".
If you post a good review at your website, and it is easy to find then it might well popup in Google and give you more visitors. One good review and a visitor could be hooked.
There's a few ideas on how to market your website, most were already mentioned but I felt I had something to add.
Good luck with your site in the future, I will try my best to post as much as possible

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Regards,
Jonny.