Inserting nodes into a tree

[%u]

Please pardon my complete lack of knowledge. Please provide some
suggestions/pointers so that I can improve myself.

Given a table containing three values (ie, myName, myId, parentId),
how does one insert those values into a tree such that the
parent/child relationship defined in the table is maintained?
Basically I'm given a file containing parents and children in no
particular order. I would like to print all children of a given
parent regardless of where they fall on the tree.

Note, this is not a school related question, simply a retard trying
to learn how to do things more efficiently.

Thanks