Rural Emergency Medicine Simulation Training and Resource - British Columbia
This page will introduce you to Point of Care Ultrasound (POCUS)in the ER.
It will attempt to cover the components of eFAST as well as some other topics and procedures.
There are now many courses on ultrasound:
for emergency care, hospital care, ICU and pediatrics.

It is highly recommended physicians take appropriate courses for their area of work. 
There are other videos on this web page going into more depth on various topics on POCUS,.

Below are some very well done instructional videos on ultrasound by Dr. Bret Nelson from Mt. Sinai Medical Center in New York covering in depth the aspects of U/S used in the eFAST.

Below are some more videos by Dr. Bret Nelson, covering other uses of ultrasound in the ER

This is a second video on Ultrasound Guided IV access,
which is very good, even though there is one above.
This final video is on ultrasound guided Pericardiocentesis.
If you are looking for a pericardial effusion in a crashing patientand are working in a remote site,
you should know what to do with it!

This is from the excellent web site "Ultrasound Podcast"
by 'Mike and Matt'.