Banding most all species of birds with seamless bands should take place around 8 days.. be careful not to wait too long as the band will not fit.. banding too early can result in the band sliding off. 

See diagram below for the proper technique to use for banding.

Each club or organization sells their own bands, some are color coded based on the year produced.

If you are interested in buying bands, email me and I will help you find the appropriate source.