JennB,
The GDL Handbook is an excellent resource and if you are serious about learning GDL it is one you should own. However, if you are just beginning to learn I would recommend you start with the GDL Cookbook. There are several editions floating around but I would start with the one found here:
www.nottingham.ac.uk/~lazwww/cookbook/
Erich
AC 19 6006 & AC 20
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