I'm starting an ecommerce site from scratch and I want to have a fairly simple order form to support around 10 products. I'd like it to have a shipping calculator, have fields for credit cards, and be able to send customers a thank you email after their order. I do have some experience with the asp code and form building but not too much. Is there a script I can download or a fairly reasonable product I could purchase to help me with this?

There are several good e-commerce open source solutions. Can't event remember all I've come across but first two that came to my mind are Zen Cart and OSCommerce

Haven't used any of those so I can't really tell how easy it is to start your own shop with those but I could imagine it's fairly simple. If you don't want to do your own template, you can get one very cheap for example from TemplateMonster.

What credit card processor are you going to use? Do you have a credit card through a bank? If so you need to touch base with them to see what gateways they use. That will usually determine which shopping carts will work for you. Then you can narrow down by gateway then by those that have a shipping calculator plugin or solution.
www.Networksolutions.com has a shopping cart as well as www.volusion.com that have wide ranging credit card support.
Hope that helps!