[Thuban-list] New to GIS

[August Zajonc]

I'm new to GIS, but have checked out many of the GIS sites that are
available and think I understand some of the basic principles. Here's
the gist of what I'd love to be able to do, and any pointers much
appreciated. 

Some open source projects have maps of developers locations, this is
what I'm shooting for.

I'd love to start with a map of the earth and/or US that looks something
like this:
http://www.fourmilab.ch/cgi-bin/uncgi/Earth/action?opt=-p&img=learth.evi
f

Then I would like to plot a series of points on this map, using a
command line driven program under Linux. These points would likely be
defined by lat/long coordinates.

Finally, I'd like to convert addresses into lat/long coordinates. 

The challenges I haven't gotten a clear answer to are:

Is there a good, freely available database that can convert locations
(zip/postal codes for example) into Lat/Long for the US, or the US +
other locations? 

Is there a good image of the US / World in the manner of the living
earth image above that is freely available?

I was thinking of using thuban for plotting the locations on the image,
but if there is some other standard that is good at handling things in a
batch manner (ie, no GUI) happy to hear of it. 

Thanks in advance for any pointers to what I know must be some very
basic questions!

August