One-way (In-Bound) link - where one site links to another site without receiving a link back.
Some of the best Link Campaigns come from submitting to directories and using SEO Social Networking
Submiting a Press Release - Not only do you get your news out to many, you also add to your SEO Link Campaigns
When you submit your site information to be linked from, make sure your anchor text (the clickable part) is one of the keywords you are trying to get your site ranked for.