There are 3 main types of links when it comes to search engine optimization. They are Editorial links, Manually Suggested Links and Self-created Non - Editorial Links.
1. Editorial links:
These are links to your site that other sites give of their own volition, because they want to make reference your content. These are the best type of links because you don't have to do anything for them and these usually are one way links. In order to get these types of links, you need to have great quality content on your site.
Write an article or create a resource to answer a question that no one else has answered well enough . Write a "how-to" article or tutorial which your target audience will be interested in.
In order to get these kinds of links you need to create quality content on your site that is interesting and relevant to your target audience . Remind readers that they can share your content as long as they provide a link back to your site. Make it easy for them to share your content by adding social media sharing buttons to that page. For example, add a "like" button linking back to Facebook, or a "tweet" button for Twitter. You can also promote this content yourself by posting links on social sharing sites like Digg and StumbleUpon.
2. Manually Obtained:
These links are obtained manually by you by convincing others to link to your site. To get this kind of link, you essentially need to pitch your site to other site owners. Keep it short and genuine. Explain why you have contacted them, and invite them to look at a particular page that might interest them. Invite them to link to that page. You could also offer your expertise through a guest post on their site. You can also offer them a chance to write on yours. Add a link to your site in your guest post. Another way to get other sites to link to yours is by hosting a giveaway on your site or provide prizes to other site owners in exchange for a link to your site.
Submit your site to site directories. Directories are basically large lists of sites. Some require payment for your submission however a lot of them are free. Visit the directories to find out how to submit a site. Once you submit a site, the directory will approve and publish the link. Focus on submitting to directories with high page authority and no spam listings. Make sure that any directory you submit to is related to your sites subject or niche.
3. Self-created, Non-editorial Links:
These are links that you've created yourself, for example, posting a link to your website when you leave a comment on a blog. These types of links have little SEO value but can add up.
Again you can build up these types of links by sharing your content on Social Sharing sites such as Digg, StumbleUpon and Reddit.
When commenting on blogs or forums, leave a link to your site in your signatures. Make sure your posts aren't just about selling your site - post valuable information, respond to queries, etc. Make sure your comments are genuine and specific to the entry. Generic comments that are obviously for SEO purposes will be detected by bloggers and search engines.
If you are going to be creating these kinds of links, just remember not to spam people's blogs or forums with your links. The blogging and forum community are tight knit, so if you regularly add good comments or posts, they are far more likely to link to your site.
Do Follow & No Follow Links:
When it comes to linking, there are do follow and no follow links. Do follow links allow search engine spiders to follow the link from one site to yours. These do follow links are good for your search engine ranking. A no follow link tag does tells Google to disregard the link and to not follow it to the target page. Specifically nofollow links does not affect page rank. This means you should not pay for links from directories or other sources if they carry the nofollow tag. Search engines are now trying to use the no follow tag to stop paid links from affecting search rankings.
Some sites will use the rel="nofollow" attribute in their site code, which tells search engines not to crawl such links in comments, guest books, etc. This no follow tag was initially created to stop spamming on blog comments, so a lot of blogs do have the no follow tag. As a result, such links may not actually matter for SEO purposes, but they are still valuable in that people reading your comment can follow your link to your site.
When it comes to the type of links that you want for your website, editorial links are the ones you really want to have. These are do follow links that have essentially been created for you. By creating great content on your site, people will naturally want to link to it from their own site. A link that only links back to your site is called a one way link. You do not need to link back to their site. A reciprocal link is basically a link swap. You link to my site if I link to yours. These links are also beneficially but ideally you want to build up a good amount of one way links to greatly improve your search engine ranking.
Diversifying your links with the different types of links listed in this article is a good way to get Google to notice your site