just installed debian on a lombard 333mhz

["Junk" <junk@riseup.net>]

i'm entirely new to the linux environment and need some help getting my
computer up and running.

i've only the command line available to me (which gui should i use?). 
during the install process i was prompted for packages(?) i wanted to
install and i accidentally cancelled out of this part and have no idea how
to get back there.

also i'm having trouble connecting to the internet when i use the following:

dhclient eth0

it doesn't seem to work.  i'm never able to ping any computers outside of
the local network .

does anybody know of a way to connect the computer to the net so i can run
apt-get?

thanks,

dustin