The Common Desktop Environment documentation set contains documents that will help you in your transition to Solaris CDE. These books will be published soon by Addison-Wesley.
Common Desktop Environment: Style Guide and Certification Checklist
Common Desktop Environment: Application Builder User's Guide
Common Desktop Environment: Help System Author's and Programmer's Guide
Common Desktop Environment: Internationalization Programmer's Guide
Online man pages are available for all development environment components.
Online help volumes are available for most of the run-time environment components.