Which table couples the orders and the product attributes of the related orders such as size, color and price?
For example, if my order contains a shirt, I need to get the color and size of the shirt through a query.
You should check the sales_flat_order_item table.
Take a look at the product_options column. Also, in that case complex porducts (Configurable, Grouped, Bundle) works as parent of the Simple (or Virtual) products so you will be able to get the reelation of items too.
product_options column in sales_flat_order_item table is in serialized format.
Is there any other table from which I can get these information?