You probably know that professional development is important. But when it comes to figuring out exactly what that means, things become less clear. What books and websites should you be reading? Which conferences are helpful, and which are a waste of time? What skills should you even be trying to develop? We decided it was time to clear the waters. So this week, we’re launching a series of Professional Development Guides—one for each of four different fields—that’ll help you take your career to the next level.