The best way to get started is to access your user information.  Simply type in the URL for your ID into your browser to GET the XML document:

https://app.feedblitz.com/f.api/user

Enter your FeedBlitz user name and password in your browser’s security dialog, and the XML for your information will appear.  How that information is presented to you depends on your browser; the FeedBlitz API does not provide an XML stylesheet as part of the response.