And you can try contacting any local mappers to ask them to get involved. You can use the Talk page on the wiki project for discussions if you want.
I don’t think its worth creating a mailing list / forum section for a small local area, unless there’s quite a lot of mapping activity and discussion there. I think it would be better to use a countrywide list to start with.
Though checking now, there doesn’t seem to be a Mexico mailing list or forum, it might be worth getting one created. Instructions for requesting a mailing list here: http://wiki.openstreetmap.org/wiki/Mailing_list#Requests_for_New_Lists
Or for a forum section, ask in the “Feedback” section on this forum.