For very religious Jews, the study of the Torah, Talmud and Jewish customs is a never-ending lifelong project.

For the rest of us, there’s “The JPS Guide to Jewish Traditions.”

This hefty Jewish Publication Society volume strives to be Judaism’s ultimate “how-to” and “how-come” compendium. The phonebook-thick desk reference includes information on just about everything in the Jewish universe, from Aleinu to zuzim.

Lifecycle events, Shabbat, holidays, prayer, dietary laws, Israel, literature, conversion, even time-honored bubbemeysas, or old wives’ tales, get their due in the JPS guide. Ultimately, the book provides a roundabout history of the Jewish people unlike any other.

Interestingly, the JPS guide was written not by a committee of learned rabbis, but by one guy: Ronald L. Eisenberg, a Tiburon radiologist and non-practicing attorney whose 20 previously published works include a book called “The Jewish World of Stamps.”

But he did have help, drawing on the collective wisdom of numerous rabbis and scholars, not to mention the formidable resources of the JPS.

In his preface, Eisenberg writes that the idea for the guide stemmed from his own “search for answers to questions relating to a variety of Jewish issues, and thus it is ultimately a book that I wanted to read.”

How much his desire may be shared by others is unclear, but Eisenberg is nothing if not thorough. The table of contents alone is more than 10 pages long (and in tiny 9-point type). But because he had hundreds of topics, subtopics and sub-subtopics to cover, the author wisely keeps his individual entries to concise lengths. With Eisenberg, it’s just the facts, ma’am.

Yet Eisenberg avoids dry and dusty descriptions. He frequently writes in a breezy style and pulls out bushels-full of Grade A trivia. To wit: The original Mayflower pilgrims, following the example of cholent-cooking Sephardic Jews they met in Holland, came up with the idea of making similar slow-cooked meals themselves. Thus was born the first batch of Boston baked beans.

Still, most of Eisenberg’s guide is devoted to religious matters, delving into the Torah itself as well as explaining various and sundry Jewish prayers. In addition to well-trod territory, such as Shabbat, Pesach or Yom Kippur services, the author illuminates lesser-known traditions such as the Kiddush Levanah, an ancient prayer of thanksgiving at the monthly appearance of the crescent moon.

Eisenberg also takes pains to honor traditions from the smaller Jewish communities around the world. For example, he includes a passage about Maimuna, a daylong celebration of Moroccan Jews following Passover. For Maimuna, a festive table is set with fig tree branches, stalks of wheat and a fishbowl with a live fish to symbolize fertility.

The author also keeps his work up to date by including recent innovations in Jewish practice, such as women in liberal congregations donning kippot, modern business ethics and the history of “Hatikvah,” the Israeli national anthem.

Anyone with a degree of Jewish literacy knows that bookstores are filled with volumes about Jewish practice and custom. So does the world really need another?

It may need this one. Eisenberg does not purport to teach people how to be more observant Jews, but rather to dazzle readers with the sheer quantity of Judaic custom, culture and ritual. Because he is not a rabbi, he writes in the voice of the Jew-on-the-street, albeit a very knowledgeable one. That helps make the guide useable as well as useful.

In the mid-16th century, Joseph Caro wrote the “Shulhan Arukh,” a landmark book intended to make Jewish law comprehensible to the Jewish masses. While Caro’s work will never be surpassed, “The JPS Guide to Jewish Traditions” makes for a superb update.

“The JPS Guide to Jewish Traditions” by Ronald L. Eisenberg, ($40, Jewish Publication Society, 806 pages).