How do I map points on a map via some sort of GIS thing?

I have a list of about 500 people and their home addresses. I want to be able to map (just by zip code) where everyone lives so I can visually see where most people live or where they are clustered on a map of Los Angeles County. Can I do this on GIS or even something like Google Earth? Any pointers or advise? I've never done this before and need all the help. Thanks!How do I map points on a map via some sort of GIS thing?
If you have gis software, the way to map a series of points is to import a text file with the locations in it. the format would be similar to:



name,address,x,y,z,....

joe,382_asdf_st,1029384.123,28302,132,鈥?br>
...



look up the addresses in google earth, note the global coordinates, and make the file. you'd want to look on the usgs website for map or aerial photo layers so that you aren't just looking at a bunch of points