I am a beginner in Unix.
I have redhat linux running in a dell work station.
my question is how can I setup a printer using the command line so that I can use the command lp filename to print, how can I define the printer name?
my printer is HP laserjet connected to network
is this a wrong place to ask this question? should I ask it in Unix for Dummies section???
as super-user, run system-config-printer
other then the printers make/model...you will also need your printers IP 
also, check if you have cups installed:
$ rpm -qa | grep cups
libgnomecups-0.2.2-8
hal-cups-utils-0.6.2-5
cups-1.2.4-11.14.el5_1.3
cups-devel-1.2.4-11.14.el5_1.3
cups-libs-1.2.4-11.14.el5_1.3