PEG stands for percutaneous endoscopic gastrostomy tube. Most are now placed in either the GI lab, or in interventional radiology. The procedure starts off with an EGD, where they look at the stomach from inside, then shine a light thru, if the light is visualized, then a small stab wound is made, and the catheter can be placed that way. This is just an abbreviated version of how it is done, steps were left off.
The regular G-tube, or gastrostomy tube is normally placed in the OR and requires a surigal procedure. It is placed in the OR when it is done in conjunction with another surgery, at least in most cases.
Care of both of the tubes is essentially the same. The most important fact is that if the tube comes out, do not wait until the next day to do something about it, make sure that it is either replaced as soon as possible, or if the patient is at home, at least insert a red Robinson catheter or even a foley catheter into the hole as soon as you can. If the G-tube procedure is fairly new, that hole will close up rather quickly and you may need to send the patient for another procedure if you wait until the next day.
Think back to when you had your ears pierced, if you ever did. You always made sure that you had something in there in the begining, or the hole would colse up rather quickly.
Hope that this helps.