Need to split one table into One row Parent, many row child and use parent key as foreign key in child. Best way?

Right now I am looking at loading it all into the parent table and then running the same query again and joining the parent table on the existing key and pulling out the new Identity key and inserting that into the child table. If this is a good way of doing it can I use a datareader destination or recordset destination to hold the data and then lookup the key. Then take that merged data and dump it into a child or should i just use a SQL Script for all of this.

Thanks.