Best link building course?

Whatever SEO strategies you use, make sure that they won't be penalized later by future updates. I've found that there aren't too many short cuts to SEO, and recent updates like Panda and Penguin are just the beginning of penalties for tactics that aren't completely on the level.

My own advice would be have some great content that people can use, and share it in a place where people will be interested in it. Whatever your subject matter is, find sites and forums that are the same subject and link build there. Build relationships with people in the same space as you are building content for, and over time they will be far more likely to share your content with their followers. Google has been showing a tendency to reward people sharing your content, and you cannot directly control that, but you can seed that behavior and try to get people to share.

The last key is to be consistent with creating and sharing content. People are more likely to share it if they know they can rely on you as a source of information. These are long term strategies that pay off on the long run.