I am in the process of finding ISBNS to add to the books I have. Most of them do not have correct meta data..  I only want to enter the information once into the opf file....

Here is an example from Feedbooks:

http://www.feedbooks.com/item/1308700/a … -episode-1

It's actually a great example of how it can be entered badly and not follow the suggested standards.
<dc:identifier id="p9780123456789">9780123456789</dc:identifier>

I believe all of the free recent books from feedbooks should have ISBNs.  This is probably my main source of books along with Gutenberg. Gutenberg do not put ISBN in their files.

This is the standard I used for coding my metadata in the .opf file: http://www.idpf.org/epub/20/spec/OPF_2.0.1_draft.htm

To understand the Calibre fields it would probably be best to look at Calibre itself. The Calibre fields I mentioned are generated from entering details into the fields called "Series" and "Number" on it's Edit Metadata screen. I wouldn't expect to see these field in any "fresh" epub from the internet. More publishers seem to just ignore metadata, or mess it up hopelessly.

I'm hoping with tools like Calibre, Sigil and Scarabee, users can start a movement towards better metadata.

(Calibre is very good, but it has an inflexible storage system of insisting "firstname, lastname-title" folders. I don't see much point in keeping all the Tony's together... (I'd much rather books by people that share a last name one another - Anne Mccaffrey and her son for example)

My dream machine would be to just point Scarabee at it and get it all nicely renamed (and refoldered) back to the way I want it. Right now I'm doing that all manually which takes up way too much time.

Normally some of the information you request should already be available :
"Publisher" : Doc-Company column / %ON variable
"Date Published" : Doc-Creation column / %On variable
For the other ones I need some epub files containing them.
Can you give me the address of a few ones that I can download ?

About the "LastName, FirstName" split you can use the "[]" modifier.
For example if the author "Doc-Author" (%Oa) column contains "Doe, John" you can get :
the last name with : %Oa[1,","]
and the first name with : %Oa[2,","]

Regards

ISBN
     <dc:identifier opf:scheme="ISBN">xxxxxxxxxxxxx</dc:identifier>

Publisher
     <dc:publisher>xxx</dc:publisher>

Date Published
     <dc:date opf:event="original-publication">xxxx-xx-xx</dc:date>

An array for Subject (up to 10)
     <dc:subject>xxx</dc:subject>

Series Name (Special Calibre field)
     <meta content="xxx" name="calibre:series" />

Series Sequence (Special Calibre field)
     <meta content="1" name="calibre:series_index" />

and an option to get the author into:

LastName, FirstName