If you did install the "desktop" meta-package, you'll have
Synaptic at hand - you'll have to use your root password to start it, the rest is more or less self-explanatory (there's a button to click to update the repository lists, another one to mark updates, a third one to start all scheduled tasks).
Another way is to use the cli:
Code:
$ su
Password:
# apt-get update && apt-get upgrade
This way, you'll get a list of upgradeable packages and will be asked if you want to do all the updates.
M.
P.S. You'll find a lot of documentation on
Debian online...
