- Know yourself. If you’re in sales, acknowledge that, if you come up with a question you can’t answer don’t be afraid to say you’ll get back to someone, don’t try and answer the question, or (even worse) use sales mumbo-jumbo to avoid the question.
Try and be the un-sales guy, you’ll catch more quality leads by being a general good guy and just simply being there than plugging your product all over.
It may be tempting to just plug, and while you might get more responses that way, the quality is going to be lower.
Essentially build a relationship with the community, as if you weren’t a vendor, as others said, look to Katie for a good example.
To expand and simplify: Answer the questions you can, Chat with the community, and be a generally nice guy, then worry about selling.
- As far as resources, i think the Antivirus vendors do a pretty good job of getting information out there, Sophos (http://community.spiceworks.com/pages/sophos) posts information linking to their “naked security” blog (http://nakedsecurity.sophos.com/) and Symantec is always posting information on the latest threats on the forum.
Personally, i think the blog approach would work best. Again, i’d say be a nice guy first, then worry about selling. There’s no need to post a link to an article from you, about you, telling people that you’re awesome.
After that, i think just simply standing on the soap box, letting people know who you are, what you do, and why you think you deserve their business works just fine.
Offers of free bacon don’t hurt either 
Looking at your site it looks like you do already offer a free version for personal use, it might help to follow Unitrends’ lead and offer a free, somewhat usable business version, that’ll get people more interested in paying you money.
As the drug dealers say, your first hit is free.
Best of luck,
-P