An easy way to build backlinks is through directory submissions. Anything hard though is worth more, so keep in mind directory submissions don’t carry the weight that in content links will. With that said there is still diluted value in link directories, just don’t focus on them.
Here are some link directories and they are organized by SEO power.
The button below opens a new window with about 100 sites. We also have the following directory sites maintained by Ultimate SEO and these are always free to list with. This site also has a directory on it built in…you can access it by the top menu bar.