I was amused by Unix utilities. They are very powerful, but they are tricky for use. Let me note down some of them as they come along.
#To tar up *.log in the current directory into a tarball called abc.tar.gz, issue this command:
tar cfz abc.tar.gz *.log
#untar
tar xvf something.tar
#To see a list of the files within a tarball, issue the following command: # Helpful as its without untarring the file
tar -tzf blah.tar.gz
# gunzip -c $file | tar xf - #AIX
# Series of files
while read file; do
gunzip -c $file | tar xf -
done < filelist
#If you only want certain directories from the tarball, do this:
tar xvzf something.tar.gz */dir.you.want/*