Here is a terrific one-stop article that will give you a sense of why, and more importantly what:
An especially nice feature about this article is that it has hot-links which take you directly to LinkedIn when you click them. A handful of examples:
- ways you can make either visual or written materials available for prospective employers to read—a whole portfolio, free!
- joining groups that are related to the industry or general area in which you want to work.
- how to tweak your profile with headline, keywords and other features in order to stand out as a strong candidate for a job.