This may surprise you, but if you write a good article and it ranks well, it can bring a good deal of traffic your way. Just have the links point to diff pages in your site for more information about the product. You used to see a lot more of this than you do now.
One thing you might try is to find an article in the "public domain" and include links to your site. It really has to be done right, but it does work.
If you are going to write it yourself, the basic guidlines I recommend are along the line of:
1) Write more like you would for print than you would for the web, with good paras 4 to 7 sent long, each on a single subject, with at least 1 link to a page in your site. If you know how to link mid page to a certain relevent area, you can link a couple of times in a para.
2) Make it a pretty good length (don't scrimp) and divide it into at least 2 pages but no more than 4 (2 or 3 is preferred).
3) Write perfect head with titles, desc, and kws all relevent to the page.
4) Publish it anywhere but your own site. You can even make good use of free webspace that come with TLDs already relevent to your content.
I had someone I worked with sometime ago that had a site that sold webspace,
seo services, webdesign, domain names etc. He wrote an article with each para devoted to each of his services explaining the fine points of each and what to look for bla, bla, bla. He then went and put it up under something like domain-names.freeservers.com (that's not it, I tried to find it), so he had kws in the name and a 2 page article at the location. He mentioned that he got something like 10 or 15 percent of his total traffic from it, as I recall.
Anyway your question was about how to write a mini site (article) and that's about how it's done.
peace...Paul