Depending on the type of CBT you're creating, and what kind of interoperability it has to have (SCORM, AICC, etc.) you may be better off using Captivate or even Breeze publisher.
You can also build content in Flash and import it into other programs like Authorware, or packages like Lectora to handle the packaging/tracking for you.
If you understand the tracking standards and are a decent AS/JS coder, you'll be able to use Flash by itself with a little elbow grease.