Shutdown process and Upgrade

[Jeetu Golani <topcat@bom3.vsnl.net.in>]

Hello,

I'm quite a newbie to Linux and emerge mainly from a MS background. I 
love Linux and use it as my primary OS though.

I have a question with regards shutting down Linux. When I shutdown Linux 
I go into tty1 and press Ctrl-Alt-Del. Now this shuts everything down 
including X and it's applications, however what if I'm in the middle of 
say typing a document, I don't get a dialog box responding to a close 
event asking me if I want to save the document or not,etc. Does this mean 
that Linux applications are typically supposed to be designed so that 
they automatically save whatever was happening when they receive the TERM 
signal. However, the time between a TERM and KILL signal is low, 
therefore if there were applications that require a lotta time completing 
what they're doing, then they may be killed before they finish their 
task. Could someone explain the Shutdown process to me?

Also I currently have Potato and I've been thinking of Upgrading to 
Woddy. How would I go about that? Could I just do a apt-get upgrade?? 
Would that upgrade me to Woody (Debian 2.4)....what is Sid?

Thanks for all the help