A quick google turned up this:
February 22-28, 2006: NFL Scouting Combine- Indianapolis. College prospects are invited to attend the main NFL scouting combine in Indianapolis, Indiana. Prospects are weighed, measured, timed, interviewed, and put through a series of tests, which include the bench press, broad jump, vertical jump, and various agility tests. Prospects also undergo psychological and intelligence testing.
February 23, 2006: NFL waiver system begins.
February 23, 2006: Deadline (4:00 p.m. ET) for clubs to designate Franchise & Transition players.
March 1-April 20, 2006: NFL Pro Days held on college campuses across the country.
March 2, 2006: Expiration date of all player contracts due to expire in 2006.
March 2, 2006: Deadline for making tenders to restricted free agents.
March 3, 2006: NFL calendar year begins.
March 3, 2006: All NFL teams must be under the 2006 salary cap at midnight. Teams may not trade until they are under the cap.
March 3, 2006: Trading period begins for 2006 after expiration of all 2005 contracts.
March 3, 2006: Free Agency period begins.
March 26-30, 2006: NFL Annual Meeting: Orlando, Florida.
April 21, 2006: Deadline for signing restricted free agents to offer sheets.
April 29-30 2006: 2006 NFL Draft.
May 23-25, 2006: NFL Spring Meeting: Denver, Colorado.
June 1, 2006: Deadline for NFL teams to send tender to unsigned unrestricted free agents to receive exclusive negotiating rights for the remainder of the season if the player is not signed by another NFL team. The NFL and NFLPA must agree to a CBA extension in order to this deadline to remain in place.
Late July 2006: NFL training camps open.
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I know the schedule is due out in mid-April so tickets would go on sale shortly thereafter I assume.
Currently the before and after June 1 cap cut rules that allow teams to split the hit in two go out the window without a new CBA since all remaining amortization hits the cap in 2006 as one of the expiring CBA poison pills.