Custom Payment Module With Credit Check

Good day

I have created a custom module that is working perfectly in testing.
The thing that I want to do now is have the content that has been retrieved via a SOAP session to be saved in the database
so that when someone goes and edit's a order in the admin panel.

They will now see the credit rating under the customer details.

I have figured out that I will need to edit the the sale/order_*.tpl to view the results.

But before I get there I will need to save my results in the orders table of the database.

So my question is what is the best way to firstly create the custom tables?
And secondly how to save my results in those tables?
And thirdly retrieving the info using the order_id?