A good place to start to learn about computing in the Berkeley Astronomy Department is http://astro.berkeley.edu/resources/computing/
You can also check out the information at http://ist.berkeley.edu/
One thing which does not seem to be mentioned on the Astronomy Department website is that you can install IDL on your laptop and then get a copy of the department license. Go to http://www.ittvis.com/download/download.asp?urlProductCode=10 to download IDL, following the instructions at http://download.ittvis.com/idl_7.0/linux/web_install_idl_all.html given by ITT. There is also some information about licenses on the download instructions page. Copy the file /apps3/rsi/idl_7.1/license/license.dat from lupus in to whichever directory the ITT website tells you to use. Then, in the first uncommented line in the license.dat file, replace lupus with lupus.berkeley.edu and save. Once you have done this, you'll need to set up your IDL environment with a .idlenv file, as described on the department guide http://astro.berkeley.edu/resources/computing/idlusers/idlsetup.html
Bill suggests using NX rather than VNC, as it is more secure and faster, but directions for both remote desktop programs are given.
See the excellent VNC tutorial written by Andrew Siemion. This incarnation of the tutorial does not make explicit that the xstartup you create must be executable in order for anything to be on your remote desktop.
NX has been installed on beast and morph. In order to locally (ie, on your laptop) run a session on one of those servers, you need to first install an NX client, which you can find at http://www.nomachine.com/download.php. This creates the directory /usr/NX/. To start the nx client, use
on your local computer. This will take you through a simple GUI setup, and then allow you to log in to the session on beast or morph using your astro account. Then, when you are done, just close the NX window and select “disconnect,” and everything in the session will be just where you left it next time you start a session.