At 4 p.m. ET on Wednesday, Peyton Manning officially became a free agent. The Indianapolis Colts filed the paperwork with the league so it's all official. This means any time can begin pursuing Manning, which usually starts with a phone call to the agent.
The Colts probably already have a good idea of what the market is for him. They also probably have numbers in mind as far as a contract goes. With multiple teams potentially involved, Manning's going to have the leverage here, the ability to choose the best spot for him and he'll get paid a ton of money for it.
Except to start seeing reports of teams "inquiring" about Manning. There's already one such report from the Denver Post that states the Broncos will "at least check out his interest" but that in the end they're likely to stick with Tim Tebow.
Almost every team in the league should be at least exploring the idea of Manning. A team with a strong need at quarterback obviously makes the most sense, but Manning is regarded highly enough that even teams with good-but-not-great quarterbacks will be checking him out.