If you find you need help in project planning, there are ways you can find, it most likely right where you work. Ask a fellow manager who works well with their team and ask for suggestions. Find a mentor in your company that you can rely on if you are stuck on planning a project.
Never panic if you have a project and have no idea where to begin. Get help from fellow co-workers, even if they are team members, they may be able to offer up some good ideas. Be open to listening to your staff. Don't be the manager or project planner who demands your way or the highway.
Ask upper management for direction if you need help. In most cases, they won't look at this as a failed effort on your part but more of a confidence builder by asking for and receiving direction.
Finally, once you have your project planning timeline and feel comfortable with it, stick to it and don't constantly make changes.
To be a successful project planner, do what the experts do and effectively plan projects. Your projects will land good grades every time.
Read my article "Project Planning - Top Ten Tips" for more useful advice on being an expert in project planning.