In order to use eCart in a Dreamweaver site you must make sure the following has been done:
1. Create a site in Dreamweaver including the local info and testing server.
2. For the testing server you will need to specify the server model or language you will be working in. You will also need to have the access portion specified.
3. Open up a page that matches the server model you choose for the testing server and save this page to the site.
4. With the page open you can add the eCart Object.
As far as tutorials, there are some files that may help in your Download Center. To get there, sign in to www.webassist.com and click on the "Your Account" link at the top right and then click on "My Downloads" on the right. On the download center you can select eCart and there should be some information on getting started.
There's also some information on the website under support.