Cary O'Donnell recently updated this manual which, as you say, provides a
good workbook for learning GCG plus some related molecular biology analysis
topics. It is written for the particular system and environment
at AFRC, so it isn't as general as some might want, but it does have
much useful help on the GCG software.
The AFRC Molecular Biology Software Training document is available on
ftp.bio.indiana.edu:/molbio/docs/afrc-molbio-man/
It is available in three forms:
o WORD-for-windows (version2) source files
o Rich text format
o ASCII text