No worries... There's too many abbreviations, I agree.
LCME = Liaison Committee on Medical Education = the body that accredits medical schools in North America. All US medical schools are and must be accredited by this body.
IMG = International Medical Graduate = Somebody who graduated from a medical school outside North America, i.e. from a non-LCME accredited school. They can be US citizens or citizens from other countries, and essentially have the same rights to seek residency as US graduates. However, their education can of course be very different from the training received at US schools.
AMG = American Medical Graduates = Graduates from LCME-acreditted schools. It's easy to distinguish between AMG's and IMG's, because all IMG's need to apply for residency through the Educational Committee for Foreign Medical Graduates (yes, usually referred to by another acronym: ECFMG).
PD = Program Director = the individual responsible for Residency program in a specific medical department.
Also note, that you can't just decide that you want to train residents, or how many people you'd want to train. Residencies need to be approved by the Accreditation Council for Graduate Medical Education (ACGME - sometimes referred to as "Green Book"). Actually, you can check which hospitals offer training in specific fields by going to:
http://www.acgme.org/adspublic/
(for instance, you're able to see that in 2006-7 there's 113 Derm programs, with 1,086 Residents, and that there's a total of 106,477 filled Residency spots)
Hope this helps,