The best way to contact other users are the forums. To get a more extensive help you can also Get Support with other resources.

The available forums are:

AdvanceMAME Help for the AdvanceMAME and AdvanceMESS emulators (advmame/advmess).
AdvanceMENU Help for the AdvanceMENU frontend (advmenu).
AdvanceCD Help for the AdvanceCD LiveCD.
AdvanceCOMP Help for the AdvanceCOMP recompression utilities (advpng/advmng/advdef).
AdvanceSCAN Help for the AdvanceSCAN roms manager (advscan).
AdvanceBOOT Help for the AdvanceBOOT utilities (makebootfat).

All the forums accept anonymous posts and allow anonymous search of the archives. If you register a SourceForge account you can also be notified of new messages.