I've been asked to address the topic of how to determine individuals in your organization with whom you seek to network. In other words, who are the individuals whose assistance/support is essential for furthering your career?
Before determine with whom you're networking, you'll need to clarify your goals -- by definition, what you hope to have achieved as a result of a series of actions completed over a certain period of time. Do you seek to enrich your current assignment, by assume more responsibility and building closer business and personal relationships with coworkers? Is there a position for which you're being groomed, through a formal succession plan? Do you aspire to a position where there is an informal (or unstated) succession plan? Do you have plans to start a business with your current employer as a client? Do you see your current position as providing valuable, albeit short-term experience necessary for you to achieve your professional goals at another organization (perhaps in another profession?)
I've touched on a few goals here that might inform your networking efforts. These and others you identify will help shape the particulars of your internal networking plan.
(Six related posts continue this discussion of internal networking. Check out part 1, part 2 (this post), part 3, part 4, part 5, part 6, and part 7.)