If you don't know where to look for software try the "Extras" (SYS:Extras) folder first, it represents AROS' "contrib" archive (DOpus, Quake, Doom, AmiChess, ...).

Try these sites:

archives.aros-exec.org

AROS main software archive

aros.aminet.net

AROS entry point to aminet, well known from the Amiga

www.dusabledanslherbe.eu/AROSPage

ported games and other programs by Yannick

Some AROS projects are hosted on sourceforge.net, try searching there.

"Bleeding edge" news about latest software releases or developments can be observed at aros-exec.org

As always, Google is your friend.