I have been researching for 7 years.I use the church records from the LDS. The LDS have a web site www.familysearch.org.I use the search capability there utilizing mostly the IGI database file.I have found a lot of my ancestors that way.Mostly I use the IGI as a guide. I go to the nearest Family History center to me and order the film that IGI come up with when I look at the detail record.If you look under the Family History Library tab you will find a Family History Catalog link and a Family History Centers link also.The Family History Catalog can be used to locate film by a place name ( General Escobedo, Mexico) and then look up the type of record you want in a certain time period.You rent the film from Salt Lake and then go to the center to read the film.Since not all records are indexed you can find other relatives on the film that were not in the IGI.The record on the film might also have more details like grandparents, parents, or padrinos or witnesses, or spouses. I know the LDS have some church records from General Escobedo on film.I just forget for what periods.There might also be civil records. I know that before a certain period( before a local church was installed there) that the inhabitants went else where for there religious activities like Monterrey. In Monterrey, I have found General Escobedo referenced as El Topos de los Ayalas.Apodaca is referenced as hacienda de San Francisco in the Monterrey records.Not all the films are in good shape.Other records that might be utilizied are protocolos and testamentes which are at the registro de civil.You almost always have to go to the location for these type of records.
Many genealogical societies have started to extract these records like the Los Bexarenos of San Antonio and SAGA of Corpus Christi.