What is an effective way to search for post-doc positions in physics?

I think this is a proper question to be answered with wiki.

Resources For Job seeker

General:

• Jobs for PhD
• Academic jobs

Physics:

• SPIRES
• American Physical Society (APS)

Astrophysics:

• American Astronomical Society (AAS)
• European Astronomical Society (EAS)
• European Space Agency (ESA)
• European Southern Observatory (ESO)

Gravitational waves:

• Gravitational wave detection jobs wiki

Talks, talks talks. If you're near graduation, you need as much publicity as possible.

Give as many talks as possible. Give talks at conferences, especially. Ask your advisor to have his friends invite you to give talks at other universities. Consider even cold-calling other physics research programs asking if they're looking for a speaker. During your talks, mention that you're graduating soon, and looking for a postdoc.

Attend as many talks as possible. Attend any talks by visitors that sound even halfway interesting. Go to conferences, and attend every session that sounds even halfway interesting. Corner as many interesting speakers as you can, and ask them if they're hiring.

Don't be shy. Most hiring is 'right place, right time', not 'perfect fit'.

If you are in nuclear or particle physics or a related field you use Job Search page on Spires (and not just for postdocs either).

And of course Physics Today and network like crazy. People who already know your work are likely to believe in you. People who know you adviser or current boss are also good marks.