Currently Raspbian doesn't maintain a forum of its own. Instead, Raspbian is discussed in the forums specific to the hardware currently supported by Raspbian.
Raspberry Pi Forums
The Raspbian community forum can be found in the Raspbian section of the Raspberry Pi Forum. Please visit this forum to ask your questions about how to use Raspbian on your Raspberry Pi.
Raspbian for the APC is currently discussed in the Other Distributions section of the APC Forum. Please visit this forum to ask your questions about how to use Raspbian on your APC.