Create Thounsands coupon codes.

i know  i can create many coupons as i want using a SQL Insert..
But is there any special thing i have to do?
my coupons are going free shipping and also 2 products free.
which tables i have to use?
Many thxs

Manually create a sample discount for each discount type
- Applied to shipping
- Applied to products

Then look at the records in the [Discount] table in the DB.
For 'Applied to products', you will also see records in [Discount_AppliedToProducts].