I'm a software developer with five years of experience and I want to start a career as a project manager. Today I'm seeking for a new job, related to management where I find myself much more valuable due to my communication skills. But it's kinda hard, because all the positions ask for previous experience, and although I have experience in project management (I'm the head developer on my team and we don't have a PM, so I end up being the PM and not coding at all) I don't have any explicit experience or course/certification.
I believe many of you are project managers in IT companies, so I ask you: are there any known steps to go from a software developer to project manager? Have you seen any successful case? Should the developer start courses on the subject? Or it's easier to start acting as a PM and get experience from that (like I did)? The knowledge on software development is a plus?
PS: I'm sorry if the question is not actually a question with only one possible answer, but I think some people here might share the same doubt. Feel free to close the question if you think it's off-topic or it doesn't belong here.