As first step, you need to properly configure your linux environment. FESA3LinuxEnvironment
If you already installed the FESA-Eclipse-plugin you can can start to work with FESA.The FESA3 hands on will guide you through the first steps with FESA and allow you to easily create a very simple FESA3 class.
Design-linked-documentation currently is not available, since there are some compartibility problems between the eclipse and the latest firefox-version. However you can as well use the existsing documentation without design-links:
file:///common/fesa/3.0-beta/fesa-model/3.0-beta/xml/doc/metamodel/FESA_Metamodel.html ( best copy + paste into browser ... no idea why the link does not work)
If you should have any problems, please do not hesitate to contact the GSI-fesa-team