"Michelle: A Biography" by Liza Mundy; Simon & Schuster

We need this book. We're full up with Barack Obama bios. Now let's hear more about his wife.

When Michelle LaVaughn Robinson Obama becomes first lady next month, three days after her 45th birthday, she will not only be the first African-American and one of the youngest and most educated women to take the job, but she'll also be one of the least familiar to many Americans.

So Liza Mundy's "Michelle: A Biography" is a welcome primer on a woman many people adore (especially Barack Obama), some people misunderstand, and almost everyone is wildly curious about.

Happily, this is not the usual rush-to-print clip job. Begun more than a year ago and published just before the election, this journalistic biography is the first major book about Michelle Obama to land, and it won't be the last.

Mundy, a Washington Post Magazine reporter, is sympathetic to the next first lady but does not gush. We get the facts in this unauthorized biography, but we also get context.

We get a pretty good idea of what kind of person the next first lady is, and we get it without the portentous tone of a formal, big-foot biographer. Which is fine, since we're in a hurry, anyway. This book is a quick read, in the style of a long magazine piece so well-written that you barely notice the length as you sprint toward the end.

Mundy also is lucky in her "girl-friendy" subject, as the author calls her. Michelle Obama, no shrinking violet, fairly leaps from the page. She is warm, funny, smart, passionate, conflicted, irrepressible, grounded, organized, maternal, authoritative, spicy, authentic and "normal."

Like so many women, she strains to balance career and motherhood. Like many political wives, she wrestles with how to be supportive without disappearing behind an adoring shadow. Her strong sense of social justice makes it difficult for her to let go of guilt about her family's prosperity when so many of the families she grew up with in South Side Chicago have so little. She doesn't hold back in saying so, which has occasionally made her a target for her husband's political opponents.

Yet it's clear from this book that Michelle was a key to Barack Obama's success in getting to the White House, and she probably will be just as crucial to his success as president.

"Michelle's most important role is" explaining "Barack Obama," Mundy writes. "She does this beautifully. It is her crucial task to humanize him, to make sense of him — to normalize him."

Mundy has done the same for his wife.