Getting started : development for Symbian

Hi Folks;

I want to develope softwares for Symbian. I dont have any idea how
would i start it. I have downloaded
CodeWarrior for Symbian Professional 3.1 (trial version) . But i dont
know what to do next
When i click on NewProject it gives me message "No devices could be
found. Please choose "Edit > Symbian Environments" to add a new
device."

Please help me to get started on it. Any help would be highly
appreciated.

Regards,
Waseem