Moving large amount of data from source to the destination tables

Hi

I'm in the process of moving large amount of data from the source table to some other destination table and delete the data after moving from the source .

The steps involved are

1. Insert one row at a time to the destination table through pl/sql code

2. Delete the the row from the source table.

1.What precautions to be taken while doing this activity on the production  .

2. How can I achive it without affecting the performance .

3.How can I reclaim the unused space with out affecting the performace.

Thanks

Sri