Here in southern California, doing genealogy research in Mexico records has been of growing interest since a signifcant part of our population has Mexican heritage. Our Chula Vista Genealogical Society (the most southerly California society!) has had several inquiries in recent months about research in Mexican records. We have referred most of the requests to a local Hispanic Genealogy Group that meets in a local Family History Center on a regular basis.
The lead article in Kimberly Powell's About.com web site/blog is about Mexican research - you can find the article hereSShe introduces the article with:
Due to hundreds of years of meticulous record-keeping, Mexico offers a wealth of church and civil records for the genealogical and historical researcher. It is also the homeland of one in every 10 Americans. Learn more about your Mexican heritage, with these steps for tracing your family tree in Mexico.
The article describes the history, Spanish rule, Spanish society, Mexican Civil Records and church records.
If you want even more information, another very helpful guide to doing genealogical research in Mexican records can be found in the LDS Research Outline for Mexico - you can start to read it here. That link takes you to the list of Research Outlines available at the www.FamilySearch.org web site.
To access the Mexico outline, click on the "M" to go to the list of Guides starting with "M", then scroll down to "Mexico" and "Mexico Research Outline" and click on "PDF". Click on OK, and the 68 page outline should appear. You can read it, print it out or save it to your hard drive (use the icon in Adobe Reader, not your [File] [Save As] buttons).