Use the emulator specific forums (e.g. MAME and RetroArch) for specific emulators that tend to generate a lot of posts. Put all other emulator queries in the general Emulator setup forum.
Some useful links when trying to figure out emulator stuff:
OmniGameZ Wiki: Check out the "Emulator Setups" section for info. Rather fledgling at the moment.
Zophar's Domain: Lists all emulators for each System
EmuGen: A good Wiki containing some detailed info for a lot of emulators
MAME World: Goto detailed info about Mame and links to other resources
Do you know of any other useful sites? Let em know below and I'll add them here.