As a newbie, the biggest disadvantages are not knowing where to look for answers and asking simplistic questions. However, "Google is your friend."
That is, just googling the words mexico cemetery index, or mexico cemetery transcription, returns as the first hit:
Mexico Cemeteries (FamilySearch Wiki), which gives an overview of what can be expected from cemetery records in Mexico, and links to state resources.
Additional google hits lead to
Mexico Cemetery Records at interment.net
Find-a-Grave as a site with Mexican cemeteries (better link to Mexican cemeteries)
some cemetery pages at Wikipedia, which can lead to the Category:Cemeteries in Mexico page
Say you're not quite as much of a newbie anymore, and you know about Cyndi's List, "a categorized & cross-referenced index to genealogical resources on the Internet."
Use the category list to find Mexico and see that there is a Cemeteries & Funeral Homes sub-category.
Now you have a link to the 3rd major international cemetery site
BillionGraves - Mexico Cemeteries
Of course, these are general results. If you were to search with more specific search terms, such as the name of a particular cemetery or look for resources in a single Mexican state, you would get more relevant hits in a google search and could drill more deeply into the sites noted above. You might also find resources on genealogical society sites, or even sites for cities or companies that own cemeteries.
Note: Find-a-Grave, BillionGraves and Interment.net are grown through user-submitted content. As such, there will be gaps and errors. Often, one of the cemetery sites will have more on particular cemeteries or regions than the others.
The main cemetery sites characterized:
- interment.net - Free. Basic lists of names of the interred, no photos, minimal information
- findagrave.com - Free. Individual memorials can include a variety of information types (dates, places, relationship links, transcripts, grave and portrait photos, etc), also many other features. Searchable from ancestry, and familysearch
- billiongraves.com - Free, but subscription-based for additional features. Focus on photos with GPS data, but additional information and record images can be attached. Searchable from ancestry, myheritage, and familysearch