Latin American Political Movements edited by Ciaran O Maolain (Facts On File: $24.95; 287 pp.) : The Central America Fact Book by Tom Barry and Bob Preusch (Grove: $27.50; 320 pp.)

For those with more than a passing interest in Latin America, a guide to the political players--something to reach for while seeking enlightenment, for instance, in the pages of that region’s newspapers and periodicals--is blessedly handy, if not downright indispensable.

Politics touches every facet of Latin American life. Parties, movements, blocs, trade unions and businessmen’s pressure groups, illegal outfits (in some countries) such as rightist death squads and leftist guerrilla bands proliferate and sub-divide.

“Latin American Political Movements” seeks to furnish a kind of score card for the whole bewildering array and succeeds to a gratifying degree.

“The Central American Fact Book” focuses on a selected region that until quite recently had not been the object of the kind of concentrated scholarly and journalistic attention that produced today’s impressive English-language bibliographies for just about every other corner of Latin America. Good Central American reference volumes have been a frustrating lack, one that the “Fact Book” does little to remedy.

The “Fact Book” is a journalistic undertaking, a polemic with a reference work’s title. To their credit, the authors make no secret of their aim: a collection of information arranged and interpreted in a manner that challenges U.S. policies in Central America.

Editor Ciaran O Maolain is equally clear that the goal of “Latin American Political Movements” is nothing grander than ready reference: a digest of basic political information, quickly accessible, for the 20 Latin republics and Puerto Rico--Central America included, of course.

O Maolain’s book tersely sketches the political background of each country and lists alphabetically the political groupings of each. If any that matter were overlooked, this reviewer didn’t find them.

Names are given in their original Spanish, French or Portuguese, followed by the English translation. Mailing addresses are listed for many. Top current leaders, a description of political orientation, and some notes about the history of each are provided.

Even the humblest political outfits in Latin America delight in identifying themselves by their initials, often an acronym. O Maolain provides these--most useful because these abbreviations tend to crop up in journalistic reports and in even more serious works as if everyone knew what they identified.

Among unexpected nuggets to be found in the volume is the intelligence that the Rev. Sun Myung Moon’s Unification Church has dabbled in politics in at least two Latin nations, Honduras and Uruguay.

Political stagnation in Haiti and Cuba can be inferred from the scant six pages that each requires for O Maolain’s listings. Seven others--El Salvador, Guatemala and Nicaragua in Central America among them--require 15 or more pages each. The editor claims to list a total of 700 organizations.

The introduction to “Latin American Political Movements” cites pitfalls the editor acknowledges for having used secondary sources in some cases, as well as information from opponents and partisans of particular groupings. He hopes major inaccuracies and distortions have been eliminated by careful editing.

No similar declaration of conscientiousness mars the determination of the authors of “The Central American Fact Book” to press their point of view.

They offer facts, assembled from a host of footnoted sources and organized generally by subject matter. Government aid, private foreign investment, militarization, farm problems are examples. Statistical tables are abundant, and a final section summarizes, in a manner consistent with their declared aim, current history in seven countries.

To the five nations embraced when that region’s citizens speak of Central America (Costa Rica, El Salvador, Guatemala, Honduras and Nicaragua), the authors have added Belize and Panama. (Belize, formerly British Honduras, is not covered by O Maolain’s volume).

The authors’ interpretation is invariably critical of most U.S. interests, public and private, that have ever had anything to do with Central America, however seemingly beneficial. They strive to perpetuate the assumption that Latin Americans do not prosper almost solely because they are exploited or otherwise mistreated by U.S. interests. This hardy myth was effectively undermined in at least three languages more than a decade ago by Carlos Rangel, a Venezuelan intellectual and editor, in his book “The Latin Americans.”