Emily Haft Bloom’s “The Bar/Bat Mitzvah Planner” opens with a premise guaranteed to make some readers crow in triumph (“See? I told you!”) and others accuse her of sacrilege (“What? Is she out of her mind?”).

Right there, on the very first page, she writes that, when you get right down to it, a bar or bat mitzvah marks nothing more than a chronological milestone.

In other words, there is nothing in the Torah or the Talmud mandating a service, a party or even the involvement of a synagogue or a clergyperson — and certainly no directive to come up with a theme no one has heard of, hire over-priced bands and entertainers, pass smoked salmon canapés, or give large cash gifts in multiples of 18.

This bombshell kicks off the first section of Bloom’s book, evocatively titled “Whose Idea Was This Anyway?” (a question that was frequently asked at our house in the months leading up to my eldest’s December 2007 bar mitzvah) and is followed by a brief but fascinating history of bar and bat mitzvot.

We learn, among other things, that girls did not become bat mitzvahs until March 18, 1922, when Judith Kaplan, the eldest daughter of Rabbi Mordecai Kaplan, read from the Torah. We also learn that according to the Shulchan Aruch, the “consummate indwelling of the holy soul in a person takes place on the 13th birthday for a male and the 12th birthday for a female.” I didn’t even know my teenager had a soul!

Above all, we learn that the modern bar or bat mitzvah (or b-mitzvah, Bloom’s snappy designation) bears about as much resemblance to its origins as a jumbo tub of butter-doused movie theater popcorn bears to a humble ear of corn growing in a field — which is to say, not much.

So why begin a book that primarily consists of tips on selecting stationery, flowers, photographers, videographers, caterers, event planners, entertainers and countless accessories and support staff for the big day with the assertion that none of this is really necessary?

My hunch is that Bloom wants to show her audience (most likely harried parents of tweens) that, contrary to popular belief and prevalent hysteria, it’s not all about the party.

Or, put differently, it can be all about the party — just don’t, she says, call it a bar or bat mitzvah.

She reminds parents and children that “the fact that family and friends will gather from all over to celebrate a 13th birthday should be acknowledged for what it is: a gift, an honor, and a privilege,” that tzedakah and tikkun olam should be an integral part of any celebration, and that the bar or bat mitzvah is an opportunity for young adolescents to reach beyond the self.

This compact, spiral-bound flip book, with a convenient pocket in the back for lists, receipts and business cards, is smartly sized to fit into a standard-issue purse, which says a lot about its down-to-earth, practical approach.

Ultimately this book works for the same reason that a successful bar or bat mitzvah does: it’s all about smart choices. If you want to throw a huge party, check out the pictures of Moroccan-themed tents and formal invitations.

Or check out what is sure to be a dog-eared section, “Hold on to Your Handbag,” where Bloom tells you how and where to economize without looking chintzy.

Whatever you’re after, it’s all here: how to find entertainers who won’t dance suggestively with 13 year-old boys, what to do if you’re “late jumping on the b-mitzvah bandwagon,” and how to handle special needs, twins, divorced parents and last-minute emergencies.

The what-to-bring lists are so thorough that I slapped my forehead more than once, thinking, “I should have done/brought/thought of that!”

The good news is that I get to do it two more times — the b-mitzvot, not the forehead-slapping, I hope. Even better is knowing the options that are on the table.

“The Bar/Bat Mitzvah Planner” by Emily Haft Bloom (Chronicle Books, 2007, 144 pages, $19.95)