Our task is to consider how to deal with questions of the form:
?What has been written about X?
The exploratory part of the research process leads you to learn about things that are outside your original question, but along the way the original question is usually sharpened and provided with a broader contextual base.

The examples here illustrate steps you might take to explore the subject of clergy in Chiapas, but can be adapted to any other topic. The order of steps follows MY preferences; you may prefer others, but I'll try to explain my choices as the example unfolds.

A W search in Annie produces this result:
   
           KEYWORD : chiapas and clergy
CHIAPAS      is in 9     titles.
CLERGY       is in 303   titles.

Both "CHIAPAS" and "CLERGY" are in 0 title. Therefore "CLERGY" is discarded.
 
There are 9 entries with CHIAPAS.
Do you want to see items found? (y/n)
 
 9 entries found, entries 1-8 are:                            LOCATIONS
     1  Bonampak, Chiapas, Mexico                       LEYBURN
     2  Incidents of travel in Central America, Chiapas LEYBURN
     3  Incidents of travel in Central America, Chiapas LEYBURN
     4  Incidents of travel in Central America, Chiapas LEYBURN
     5  Incidents of travel : in Central America, Chiap LEYBURN
     6  Mexico human rights in rural areas : exchange o LEYBURN
     7  Mexico : the uprising in Chiapas and democratiz LEYBURN
     8  Palenque: the Walker-Caddy expedition to the an LEYBURN
     9  Zinacantan: a Maya community in the highlands o LEYBURN
Annie (i.e., our book collection) is simply not big enough to have much on Chiapas, so it makes sense to use a larger catalog, one that's both reasonably easy to learn to navigate and likely to have good holdings on the subject in question. My choice for such a catalog is Harvard's HOLLIS, which you can connect to in several ways:

Here are results and discussion from my HOLLIS searches.

Other libraries may be more fruitful for some subjects. The Latin American collections at University of Texas at Austin and Tulane University produce some different materials.

Another important resource is Historical Abstracts, which we have in the Library on CD-ROM. There are basic instructions for searching HA on the workstation (which also contains America History and Life, the American History database). Here are some examples from my search in Historical Abstracts.
WorldCat (accessible through FirstSearch) is a database of book holdings in many libraries, and can be useful if you need to know WHERE a book is held (for example, which Virginia libraries have it). Each search in a FirstSearch database costs the Library $.50, so FirstSearch is probably not the place to begin an exploratory search. Here are examples of my searches in WorldCat.
Another essential tool is the Handbook of Latin American Studies, available in paper form in our Reference collection (REF F1401.H233). It's an annual index of research,
A selective and annotated guide to recent publications in Anthropology, Economics, Education, Geography, Government and Politics, International Relations, and Sociology [Social Sciences volumes] Art, History, Language, Literature, Music and Philosophy [Humanities volumes]
prepared for the Hispanic Division at the Library of Congress. The volumes are organized by TOPIC and GEOGRAPHY (e.g., History: 19th and 20th Centuries: Venezuela; History: Mexico: Colonial; Literature: Translations: Anthologies; Economics: Argentina, etc.) At the end of each volume are Subject and Author indexes.

It is possible to search the HLAS electronically via the Library of Congress (LOCIS), though the searching and display interface is not very user-friendly. Here is an example of searches and results. You can connect to LOCIS and try searches in the form

                  find s subjectword;f=gb
The examples above illustrate an exploration of a subject area; while you wouldn't find everything written on 'clergy in Chiapas' by following my strategy, you'd have a much better understanding of the dimensions of the literature on the Church in Chiapas, past and present, and you would certainly encounter unexpected gems (probably with their own bibliographies to lead you to other sources).

Note that we began with books and used the "controlled vocabulary" of the LC Subject Headings as a means to enlarge the scope of inquiry and direct us to related Subjects and books. We could then have done more focused searches in Historical Abstracts and Handbook of Latin American Studies, though in the examples above I used the more general search terms.