I'm not there yet, but have any of you gotten to the point in your
research where the records are written in Latin? I'm not even sure that
this will be an issue in Mexico.but just in case you are back that far
here is a tutorial on beginning Latin that might help:

http://www.nationalarchives.gov.uk/latin/beginners/

also related to this is:

Palaeography: reading old handwriting

http://www.nationalarchives.gov.uk/palaeography/

I found this information on the Genealogy Guys podcast:
http://www.genealogyguys.com/

They very seldom talk about things specifically related to Hispanic
Genealogy, but often talk about things that could benefit us in our
genealogy.

One thing they mentioned is something I have yet to fully investigate.
Seems that Family Tree Maker will hold the two name Spanish style of
Surnaming together in the right order with the use of a slash or
back-slash.

At the same time they did give a good plug for the Legacy software that
Victor uses in that it has fields for each of the names I believe.

joseph