Need to Create a two-way transitive trust with a 2000 forest.

I have a brand new 2003 single domain forest. I would like to create a
two-way transitive trust with a 2000 parent-child forest. What is the order
in which I need to do this or does it matter. Do I need to create a trust
with both 2000 domains or do I just need to create a trust with the root
domain. Both 2000 domains have resources that will need access to the 2003
domain. The 2003 FFL is Windows 2003 and the DFL is Windows Server 2003. The
2000 Domain is in Native mode. I can ping the DC’s by name in both
directions. Thanks.