asp.net using c# code

Question

I need to be able to do an Amazon lookup based on ISBN for several books which are listed in a local database.  I need the book info and seller information.
I'm not sure which Amazon product I should be using.
Where would I find sample code?
ColdFusion is preferred, but Asp.Net Using C#is a good alternative.
I've looked through several of the documents, but don't find an answer.
A lot of the documentation listed is before the signed request change, and it seems there have been recent changes that are not in the samples or help files.
When I signed up for Amazon support, they said they don't support the Advertising API.  I'm not sure I should be using the Advertising API.

Please Help Me!

Norm, [email protected]