Whenever you create any triggers on table that gets store in the system views of sql server 2005 ie sys.triggers. Now question is how to find triggers that are applied on table, you can query on sys.triggers which is mentioned below.
SELECT name FROM sys.triggers WHERE parent_id = OBJECT_ID(‘tablename’)
To find the text of the trigger you can execute sp_helptext ‘triggername’
To find out more about triggers follow the link SQL Server 2005 – How to create DLL Trigger