[tex-live] Install from DVD, update thereafter from Cambridge

[Philip TAYLOR]

Dear Colleagues -- I will need to install TeX Live 2008
for various friends in the near future, and will be using
the ISO image to burn a DVD from which I will then install.
Following installation (Scheme: full), I would like to perform
a routine upgrade from Cambridge, and to leave the installer
configured such that all future updates are also taken from
Cambridge.  Could you please advise me how best to complete
the last two steps ?  Also, can TLMGR integrate with the
Windows Scheduler such that it could be set to perform
an automatic update at (say) 04:00 every morning ?

** Phil.