deadlocks in multiple-triggers environment

hi
i have a stituation a situation where i have multiple tables, and multiple triggers on all of them.
at least 1 or 2 triggers on at lease 4 different tables does updates to main cache table.

now.
i have tasks which involve simultaneously (from different machines even) modifying all of the "source" tables.
and i get some deadlocks.
what is the best way to fight deadlocks?
how to find exactly what happened deadlock - which command, which trigger, which function?
how to avoid them (deadlocks).
i can't lock all tables for update, because they happen constantly.

any clues?
pointers? urls?

depesz