I have a Dell XPS M140 notebook with a gig of RAM already installed. I have replaced the RAM in desktops lots of times.....(very easy), but I have never attempted to replace the RAM in a laptop before. Can someone please explain how to do it (step by step) and what would be a good brand of RAM would be to put in my DELL? I have FREERAMPRO and it is showing that I am down to 96 MB of ram when I play WOW. Thanks in advance for all the help.

Dell should be happy to explain how to access the RAM module(s) in your notebook. Notebooks almost always use SO-DIMM modules; besides finding out how to get at the module(s) (usually under a hatch on the bottom, or under the keyboard), they can tell you the specs of what RAM you will need: DDR or DDR2, speed, latency, etc.
On some notebooks one of the memory locations has permanently-installed memory and you are only able to access/change one module.