LOS ANGELES _ Before auditioning for “American Idol,” Kelly Clarkson worked as many as three jobs at once. She liked to stay busy, she said, because otherwise she would “get mopey.”

After Wednesday night, however, “I don’t see mopey in my future.”

Clarkson, a 20-year-old from Burleson, Texas, will be a very busy woman indeed, what with her new recording career and all.

She was the overwhelming winner of “American Idol,” capturing 58 percent of the more than 15.5 million phone votes cast after she and runner-up Justin Guarini performed their final songs of the competition Tuesday.

Her first single, “A Moment Like This,” which she sung Tuesday and at the close Wednesday’s show, will hit stores by Sept. 17. A full album will follow in November, and she’ll also appear on the “American Idol” compilation CD.

It took a moment for Clarkson to understand she’d won. However, she said the noise in Hollywood’s Kodak Theatre was so loud when co-host Ryan Seacrest made the announcement that she didn’t hear it. It wasn’t until Guarini hugged her that she realized what happened.

“I was just standing there like, `Duh…,'” the self-effacing Clarkson told reporters after the show.

With a big voice and great range, she had emerged as the favorite in the final weeks of the show, especially after Tamyra Gray was surprisingly voted off on Aug. 20. She nailed pretty much every performance she gave; not that she would say so.

“We’re all performers, so there’s always some of `I could have done that better,'” she said of herself and her fellow contestants. “I’m my own worst critic, but in the end I think I did an OK job.”

Clarkson’s first recordings will be overseen by Simon Cowell, the “Idol” judge whose record label gets to sign the winner. Although he earned a reputation as “Mr. Nasty” during the course of the show, he has nothing negative to say about Clarkson.

“She’s going to be a big star,” Cowell said. “Any singer who comes in (to the music business), they’ve got to be visible to the major producer-writers in the world. Because of this competition, they all know her.”

Clarkson’s fellow finalists, all of whom appeared on Wednesday’s show, also praised her, calling her “down-to-earth,” “sweet” and “deserving.”

That last comment came from runner-up Guarini, who will almost surely get a recording deal of his own. He says that as Seacrest was making the announcement, he was actually thinking, “Let it be Kelly.”

“I can’t sing those songs nearly as well as her,” Guarini said.

“Idol” has been the summer’s biggest hit, with more than 18 million people watching Tuesday’s final performance showcase. Fox has already ordered a second edition, which is likely to premiere early next year.

No deals are in place yet, but it’s likely that co-hosts Seacrest and Brian Dunkleman will return, along with judges Cowell, Randy Jackson and Paula Abdul. Those involved with the show, however, weren’t ready to think about those details on Wednesday.

“I’m just going to celebrate tonight,” executive producer Nigel Lythgoe said. “I’m going to get very drunk.”