According to ESPN's Adam Schefter, if the NFL Players Association ratifies a collective bargaining agreement with the owners on Monday, NFL teams would be able to re-sign their own free agents as early as this afternoon.
Schefter's timeline also has teams being able to discuss trade parameters and negotiate with other team's free agents (restricted, unrestricted) this afternoon, though trades would not be official until Saturday, July 30.
Teams would be able to sign other team's free agents beginning at 12pm ET on Tuesday, July 26, but those contracts would not become official until the 2011 league year begins at 4pm ET on August 2, eight days after the NFLPA will have ratified the CBA and potentially up to seven days after a player and his new team agree to terms.
Members of the NFLPA Executive Committee were scheduled to meet at 9am ET on Monday, though Albert Breer of the NFL Network reports that a final document is not expected to be ready for the committee to vote on until late Monday morning. Once the committee recommends the agreement and recertification of the union, the 32 player representatives will vote on the same issues via conference call, turning the matter over to the ten plaintiffs in the Brady v NFL antitrust lawsuit.