Blue Ivy's mama is back in a big way this weekend in Atlantic City!

Starting this Friday, Beyonce begins a four-night stint at the brand-new Revel casino in New Jersey -- her first professional performance gig of any kind since welcoming her daughter Blue Ivy Carter this January.

The star, 30, released a behind-the-scenes video in advance of her big comeback concerts, including in-depth footage of planning sessions, music sessions and sweaty dance rehearsals.

"We're basically warming her up and getting her back into shape," dancer/choreographer Danielle Polanco says. "Stretching her out . . she hasn't been working out in I don't know how long!"

"I feel a little nervous," Beyonce, radiant in little-to-no-makeup, says on-camera. "I'm enjoying being a mother so it's like going back to my old job, and it's a little strange," she says. "But it's important that you don't lose yourself and still have your own passions. And so I'm back to work, I'm back to business."

Chatting up the show with her team, she explains: "What I'm trying to say in the show is, 'Yes I had a baby. It just made me more grounded and more like you."