Everyone here knows how I (incessantly?) harp on the fact that you need to balance the creative with the business side of media making. If you want to make a career out of this - you need to know what you're getting into, how much things actually cost and how that affects what you do and how you do it.
Here's something that will help you as you get started and don't have the cred to spend money to solve your problems (something I never advocate). So embrace your inner entrepreneur and give this Bootstrapper's Bible a read. [PDF download]
It is truly inspirational, especially in this era where many of the opportunities out there are right at our fingertips.