The primary communication channel is the IRC channel of the Padre developers. It is located on the irc.perl.org server and it is called #padre.
After asking a question please be patient as the people might be busy doing other things so it can take some time till someone responds.
The Padre development mailing list is another way to ask for help. It is usually slower than IRC but it also means you don't have to be connected to the channel while waiting someone to answer your questions. To join the mailing list please visit the registration page of the padre-dev mailing list.