Sorry, you can't script BotG. We don't have the enums.
To get started there's a good tutorial in the BW2 Modding WIKI. There's also some good tutorials there for using the landscape editor.
For actual scripts and such we do have a Script Library which contains most of the scripts used in the various maps. There should be enough there to get you started. Also look in the Lionhead boards in the modding forum for the Post Your Script Functions thread by 00din.