Creating an Individual Development Plan will help you set well-defined and realistic goals and create a clear plan on how to achieve them. It'll also help your mentor monitor your progress.
Learn more about how Individual Development Plans may help by viewing this presentation from The Graduate School.
Here are two examples of Individual Development Plans to guide you:
Additional worksheets and helpful information are available on this PDF, also from The Graduate School.
Remember that these are living documents. As you evolve professionally, your circumstances and priorities will be ever-changing, so be sure to revisit them frequently.