You can contact the team in several ways:

Mailing list

The best way would be through the mailing list, the address is ubuntu-sugarteam AT lists DOT ubuntu DOT com. You an join the mailing list at http://lists.ubuntu.com/mailman/listinfo/Ubuntu-sugarteam.

IRC

We can also be found on IRC, on the Freenode server irc.freenode.net at #ubuntu-sugarteam. Contact the Sugar Labs development team to find out if anybody there is interested in participating.