How to get all metadata

Hi
Sorry for newbie question, but i dont know how to get all metada from data 
objects. I want to get metadata from for example FITS files -  TELESCOP, 
CCD-TEMP, OBSERVER .... .
I am able to get data from *SScell. 
Please send me a simple example of how to list all metadata from data objects.
                        Radovan Stas
                        radoone at szm dot sk