I am working at learning SEO for an ecommerce business as well. The niche I am planning to start with is, well, I don't think there is much competition for it, I will find out. However, assuming one was say selling supplements and/or vitamins online, how does one do SEO for this?

For example, in regards to linkbuilding, how would you go about doing that? Do you just write articles around the Internet on different vitamins and so forth? It just seems so confusing!

For example, do the top-rated vitamins sites have teams of people devoted to SEO in which they do just these kinds of things, like go around and post on forums relating to the subjects and write articles and so forth??

The niche I am planning to begin with you can't really write articles about I don't think, so I will need other methods of linkbuilding.