NEW YORK — Let the bidding and begging begin.

The NBA’s free agency period has opened, with LeBron James leading perhaps the deepest group of players to ever hit the market.

Teams could begin making their pitches at 12:01 a.m. EDT Thursday, and some were getting started quickly.

Atlanta’s Joe Johnson was expecting early visits in Los Angeles from the Hawks and New York Knicks, with the Atlanta Journal-Constitution reporting that the Hawks were prepared to offer the All-Star shooting guard a maximum salary contract.

Things get interesting later Thursday, when the New Jersey Nets and Knicks are scheduled for visits to Ohio to meet with James, the two-time MVP who heads the class.

It includes other All-Stars such as Dwyane Wade, Chris Bosh, Dirk Nowitzki, Amare Stoudemire and Carlos Boozer; veterans such as Shaquille O’Neal and Ray Allen; and young up-and-comers such as Rudy Gay and David Lee.

“We’ve never had anything like this in my time that I can remember,” New Jersey Nets president Rod Thorn said. “There have been big-time free agents before, but never this many teams that are trying to woo them. So it’s unprecedented.”

Teams were headed around the country to meet with players, though the Mavs were saved a long trip when Nowitzki informed them he would meet with them Thursday in Dallas — with the message arriving while president Donnie Nelson was at the airport preparing for a flight to Germany.

Showing they planned to be active, the Knicks confirmed on Twitter they would also meet with Wizards swingman Mike Miller in Los Angeles. But they would do so without team president Donnie Walsh, who went directly to Ohio in preparation for Thursday’s meeting with James.

Pat Riley and a Heat contingent also began their free agency tour in California, where teams were hoping to meet with Stoudemire. They also planned to meet with Johnson.

It promised to be a wild first few days of July, with plans changing by the minute.

“You’re not in control, as much as you would like to be,” Timberwolves president David Kahn said. “I don’t think any team feels right now they’re in control of the situation. There’s too many teams with room. Too many fine players out there. I think in those types of situations, it’s best to be really nimble and change course if need be.”

Kahn said early Thursday that Gay would visit Minnesota later in the day and Lee would arrive on Saturday. Gay is a restricted free agent, so Memphis can match any offer for him.

Even the Clippers, those longtime losers, thought they could be a player this summer. General manager Neil Olshey announced in a statement the team had already contacted several players and confirmed it had scored an invitation to meet with James.

“At that time, we intend to present the many reasons why his joining our organization is the best possible choice he could make,” Olshey said.

Talk of James’ destination seems to change by the minute. He was considered a lock for Chicago in one report, then seemingly guaranteed to head to Miami in another. The rumor mill spun so out of control that an online sports book simply stopped taking action on James’ next team.

Bottom line: James can get perhaps $125 million over six years by staying in Cleveland; $96 million over five years if he goes. (The exact figures can’t be determined until next season’s salary cap is set in July). But leaving could put him in a better position to win a championship.

Thorn is headed to Ohio, where James will welcome suitors to his home state Thursday. He’ll be joined by new Nets owner Mikhail Prokhorov, coach Avery Johnson and hip-hop superstar Jay-Z, a part-owner and James’ longtime friend.

The Knicks plan to drop in on James, too. They can afford to pay him and another classmate the maximum next season, which might be what the Knicks need to finally get going again after a franchise-record nine straight losing seasons.

“We’ve had to live through some tough times in order to get where you think you start rebuilding the franchise,” Walsh said. “We have that opportunity now. How well, how fast we can rebuild the team can be shortcut by getting great players.”

They’ll have plenty of competition. The Heat, Nets, Chicago Bulls and Los Angeles Clippers also can afford to offer a player about $16.6 million next season, which is the maximum someone with James’ amount of NBA experience can make. Chicago and New Jersey made trades in recent days to push them closer to joining the Knicks with enough to offer two max deals, and the Heat can keep Wade, give an additional max contract and have enough left over for another quality player.

Top players rarely leave via free agency because NBA rules allow their teams to offer them more money in the long run. The difference comes not in the first year of a new contract, but in the raises.

A player signing with his own team is eligible for annual increases of 10.5 percent, while a new team can offer only 8 percent bumps. The home team can also offer six-year deals, whereas players joining new teams can get only five-year contracts.

The Knicks traded away Jamal Crawford and Zach Randolph — the NBA’s top sixth man and a first-time All-Star, respectively — to get their $34 million in cap room. New Jersey, which shipped out Jason Kidd, Richard Jefferson and Vince Carter in recent years, went just 12-70 last season but hopes for a quick turnaround. Miami essentially left Wade to play by himself this season in exchange for the chance to get him some superstar help next year.

“It is an ’all-in’ strategy, in that even when it works, you’re going to have to operate with a very low payroll,” Houston Rockets general manager Daryl Morey said. “If it doesn’t work, it can be catastrophic in terms of if you strike out, it’s going to be very difficult to be competitive.”

Morey used his Twitter feed to announce he’d met with Bosh in the opening hours of free agency.

“He is about winning so I focused on how (with) Houston he can win a championship,” Morey wrote.

The clock started ticking four summers ago, when James, Wade and Bosh passed on maximum-length extensions on their rookie contracts in favor of shorter deals that allowed them to opt for free agency this summer.

Momentum kept building as fears grew that owners will seek radical changes in the length and value of contracts next summer when the league’s collective bargaining agreement expires. That made it wise for a player like Nowitzki, even if he has no intention of leaving Dallas, to exercise his early termination option now and sign a new deal under the current rules.

Toronto expects to lose Bosh. If the All-Star forward joins James or Wade, or both, that team figures to become an immediate championship contender. Boston won the title the year after assembling its Big Three — which could now be broken up with Ray Allen on the market — and the Lakers have reached the finals every year since acquiring Pau Gasol to complement Kobe Bryant.

Numerous teams are now dreaming of similar pairings once deals can be signed on July 8.

“You look at the teams that have an awful lot of cap space, there could be a lot of power shifting in this league,” Minnesota coach Kurt Rambis said.