Adding Mac clients to win2003 network

Dear Colleagues,
My employer has just bought 5 Mac client(i think tiger/panther). I have been asked to make it possible for users to log on throgh these clients and have access to the windows network. I am running windows active directory on windows 2003 standard edition servers.
I have searched the net for information on how to do this but no help.
Please help as time is running out for me.
thanks