Here's a list of some very useful sites/tools needed developing WeBuilder plugins:
pdScript IDE (Precision Delphi Script IDE) is a development environment for writing the code and designing the forms (GUI) in a Pascal Script language.
http://www.be-precision.com/download/
This tool is great for creating the plugin GUI, and the values created can easily be adapted from Pascal to FastScript.
And you get info about all the various options for each object type. (A lot which is not listed on the WebBuilder plugin/classes page.)
Delphi Basics: This web site provides help and reference for the fundamentals of the Delphi© language. It gives an introduction to the Delphi Object Oriented Language for newcomers, and provides a ready reference for experienced programmers.
http://www.delphibasics.co.uk/
A COMPLETE list of available Delphi/FastScript functions. (MUCH better than the default Webuilder plugin/functions page.)