Metadata entry

Is it possible to cusomise the entry of metadata to an image. I want to 
create/edit just a few fields so that my wife and others can easily 
update the information. Presumably like a template but allows for 
different data to be added to each image - not a batch edit. This would 
be really useful; since there are so many metadata fields.

[It would also be useful to have a special field for date - for old 
scanned images; so that we can input e.g. circa 1935 and not have it 
mixed with keywords, caption etc.]

Thanks

Alan Seal