Link building in a competitive e-commerce market - Tips?

Sorry for yet another noob-like SEO question. Again, this really is not my first time around SEO, but all my past work has revolved around community forums where new content was generated every minute and link building happened on its own. And when I did have to do it I was linking to helpful content, not products I was trying to sell. I’m now dealing with e-commerce sites, where link building is considered evil in most places when you’re trying to build links to your online store(s).

So here I am, looking for relevant online resources that I might be able to contact and get them to link to us, or blogs/forums where I can post a comment and add a link myself. The first challenge is, I am nothing close to an expert in this industry and cannot answer questions or post content in forums or blogs without consulting with my coworkers. The best I can really do is get one of my coworkers to write an article and try to get it posted somewhere, and include a link back to our site. I could try and focus on forum technical discussions and get a coworker to come up with replies that I can post in an attempt to become a contributing member, and then sprinkle in some links with every other reply… but that would be extremely time consuming and I’d run the risk of being banned for self promotion.

The next challenge is that there aren’t many resources that show up in keyword searches for the product categories we sell that aren’t competing online retailers. The top results (subject authorities for our target keyword terms) are retailers, with the exception of the actual manufacturer sites - neither of which we have any hope of obtaining links from. So where do I look to build links? If I find a relevant informational resource that has some or no PR, would it make sense to try and obtain links on those sites? What if maybe the site itself isn’t focused specifically on our market but has good PR? Do I waste time on general resources (like an, or general sites that don’t use nofollow links) and try to get a market-specific article posted there, with links pointing to our site?

The last challenge is that we do not have any real content posted on our site outside of the products we sell. There is nothing worthy of linking to that we can promote that doesn’t include our product offering. I know the answer is to try and build content, but that’s easier said than done here. Yet, trying to link to our product categories will be tough, and in some cases will get us banned from community sites. So…

With all that in mind, where does it make the most sense to focus my efforts on link building?