You may have heard that you'll get the best optimization under your keyword phrase if you can get other sites to link to you. It's true. Google sees a site that's all by itself, an island, and it thinks, "This site must not be too important because nobody is talking about it."
So your job is to get backlinks, or links from other sites to your site. It's one of the best ways to get the top of the search engine rankings.
But not all links are created equal. Here's how you want to think about backlinks:
1. You want your keywords to be in the anchor text for the link. An example I use is that you may have a site about training English Sheepdogs and may be optimizing for the phrase "training English Sheepdogs." You know how sometimes you'll see links that say "Click here" and "Click here" is the blue part – the link? In this case, you want "training English Sheepdogs" to be the actual text that is linked to your website.
2. Ideally, you want the links to your site to be from sites that are similar to your site. So here, you'll get the best results if the sites that link to you are also about training English Sheepdogs, or training dogs, or English Sheepdogs in general. When Google sees a similar site linking to yours, it thinks, "Site A is relevant to this topic, and it's linked to Site B, so Site B has a better chance of being relevant to this topic as well."
3. The best links are also from high-authority sites. This just means that the bigger and better the site in your field, the more you want links from it. SEO works on a currency called "pagerank," and the simple way to imagine this is to think of a site as having a certain amount of "juice." Links coming into the site add to its juice, and it gives the sites that it links some juice. Sites with higher pagerank (more juice) pass along more of that rank when they link to you than little sites.
Be sure to check out the rest of my articles for information how to make these backlinks YOURSELF without having to bug other site owners for them!