As for the first question, you just need to append to /etc/fstab, one
additional line per partition on your hard drive. The whole specification can
be read with the following command:
$ man fstab
Of course, editing /etc/fstab requires administrative privileges, hence
'sudo'.
As for the second question, have you actually made a lot of customization to
you session? If not, you can simply remove the configurations files in your
home folder. That will bring back the default configuration.
Feel free to ask for precisions.
