Copying teams and divisions is the fastest way to associate a large number of teams to a new season. This is the process to follow when one season finishes and you wish to open the new season. It is always easier to 'bring everyone over' to the new season and remove the teams that aren't coming back, than to add all the returning teams one by one.
To do this, simply select the season you want to copy info from (e.g. Winter 2014) in the drop down list at the BOTTOM of the page, and click "Copy". This season refers to the season in the drop down at the top of the page.
A couple of key things to consider:
As there are other ways for teams to be associated to the season, a certain level of care needs to be taken when associating teams into the new season. The general rule of thumb is that if there are already teams in the newest season, tick the box that says 'append to existing divisions and teams'. This will essentially add everything to the new season in addition to what is already there instead of removing the new teams.
SECONDLY, you must be careful not to accidentally copy from the NEW season to the OLD season - for example, if you want to copy Autumn registrations to Winter, you must make sure that "Winter" is selected in the drop down list at the top of the screen and "Autumn" is selected as the season you want to copy from AND NOT THE OTHER WAY AROUND. If you do it the wrong way around you can accidentally overwrite all your previous season's registrations.