There is no substantial documentation yet.  Volunteer authors are
more than welcome.  Here are some examples to get you started.

# Search all files in specified packages for a regex
$ dgrep <pattern> <package>...

# Search through all files in all installed packages for a regex
$ dgrep <pattern> '.*'

# Same, but also search inside compressed files
$ dzgrep <pattern> '.*'

# Calculate the total disk space usage of all files contained in all
# installed packages whose names begin with 'lib'
$ dglob -0f ^lib | xargs -0 du -c | awk '{sum += $1} END {print sum}'

# Fetch most recent version of package
$ debget <package>

# Fetch a specific version of package
$ debget <package>=<version>