Converting to LDap

OK, If there is a title for someone less than a newbie (that does not imply mental retardation)- then that is me!!

Lemme splain:
Running a tiger server (after an interesting upgrade process), the user directory (?) is set for "/netinfo/defaultlocalnode" - evidently that needs to be a flavor of LDap if I want to set up portable home directories/ mobile users/ network user directories (what ever you want to call them this week).

Question: How do I convert the /NetInfo/DefaultLocalNode to be LDap??? (please use small words, I'm not the brightest bulb in the pack)

Thanks,

PoserAdmin