Read your graduate student handbook to find out your doctoral program's requirements and your expected timeline for completion. Ask questions about any guidelines that confuse you early on to avoid complications down the road. Write out your own version of the timeline to keep you on track for the next few years.
Seek out mentors among graduate students who are further along in the program and also among your department's faculty. Take classes with them, visit during office hours and invite them out for coffee to discuss their work. Gather information on the best courses and advisers for your project and working style.
Take courses that will allow you to begin exploring a topic for your doctoral dissertation--a piece of original research--and writing about it.
Choose a doctoral committee of faculty members to guide you in preparing for your comprehensive exams and creating a research proposal for your dissertation. Consult your mentors and your own experiences during classes to choose a dissertation adviser who is knowledgeable, responsive and available to students. Ideally, you want someone whose former students have successfully defended their dissertations in a timely fashion and gotten jobs soon after graduation.
Ask colleagues to see examples of the lists of books and articles they read for their exams, as well as their research proposals. Don't rely on general graduate school survival guides--find out what worked best for people who've gone before you.
Keep up with the major journals and conferences in your field. Apply to write book reviews for the journals and to present papers at the conferences. At professional meetings, make an effort to introduce yourself to scholars whose work you admire.
Apply for grants and fellowships from sources outside your university. Future employers will look more favorably on your job applications if you can demonstrate a successful track record in getting funding.
Use term paper assignments to write papers in your area of expertise that you can present at conferences or rewrite as publishable articles or as sections of your dissertation.
Follow up on new professional associations with a polite email expressing your regard and recapping how you met and what you talked about during the meeting. Keep in mind that people you meet at conferences or meetings or experts who come to speak at your school may later be asked to review a book you've written or to make a recommendation about whether or not to hire you.
Consult your mentors at regular intervals to see if your professional development is on track. Ask explicit questions about the publication expectations for scholars in your field and how these expectations will affect your marketability for research funding and jobs. Then see how the advice you're receiving matches up with the experiences of your recently graduated colleagues.