In October 2000, 16 postdocs gathered at the GREAT meeting in Savannah, Georgia, to discuss a variety of issues (see accompanying article  for more details). One task before the group was to compile a list of practical advice for would-be and fellow postdocs. The Postdoc Network is GREATful to these postdocs for allowing us to publish their sage advice.
Things to do before or soon after you start your fellowship
Get a formal appointment letter detailing your title, pay, benefits, length of appointment, vacation/personal time, project, and future salary increases. Click here  for an example appointment letter from the University of Pennsylvania's School of Medicine.
Be wary of principal investigators (PIs) that "promise you the world"--they may not follow through.
Set the tone of your mentor-mentee relationship early--Be enthusiastic; don't lie about or exaggerate your qualifications and expertise.
Investigate institutional resources and core facilities.
Know your rights as a fellow. See the guidelines for NIH's National Research Service Awards , and you can check out the Postdoc Network Database  for links to examples of institutional postdoctoral guidelines and policies.
Apply for your own funding. Not only can your own funding support travel, supplies, or other items, it allows you to start an independent project (i.e., something you can take with you) and be less constrained in dealing with your PI.
Once you are there
Be proactive--get involved with your home institution's postdoctoral association (or start one).
Get out of the lab and network with your peers and others.
Develop relationships professionally and scientifically with faculty and other postdocs. (Faculty can be useful in the future for letters of reference.)
Keep an eye on the future; explore other career opportunities.
Try to be open and honest in your professional relationships.
Develop a 5-year plan for your career (and review it regularly).
When you are established
Conduct informational interviews  to learn about career options and get real-world advice.
See a career counselor about your career questions and path. Consider contacting your undergraduate (or graduate) institution's career office if there are no services available to you at your postdoctoral institution.
You may want to consider taking a self-assessment test  to help you determine your path. (The career professionals cited above can help you with this).
Have faith in yourself and your abilities.
Act like a colleague--don't act like a graduate student by asking your advisor to do things for you.
Just do it (sorry, Nike)--it is easier to beg for forgiveness than to ask for permission.
There are other options--you don't have to be a postdoc if it's not for you.
Always ask questions--don't be afraid.
Have short- and long-term goals--don't just live "in the moment."
Have a backup plan for everything--both your project and your career.
Remember, you can always leave and go to another lab. (It's easier than you think.)
And most important ... whatever you are doing, don't give up!!!