Completely brand new to GIS - Help picking technology from the pros

I would go with GeoServer It's the easiest to setup yet very powerful and completely OGC compliant. Lots of documentation and a very active user community... join user list serv.

Using GeoServer is the way to go if you want services adhering to the OGC spec. Openlayers is the client side library you're looking for (using google maps and bing).

In my experience however, only coding in javascript kills my productivity. I spend hours hunting small bugs, even with developer tools and firebug. Therefore, I write most of my code in geodjango. The data is stored in PostGIS, used by GeoServer to do everything I need. So for admin screens and workflows I'd recommend having a look at geodjango.

If speed is important, then MapServer is a better choice than GeoServer. As of 2010 MapServer is a faster WMS server than GeoServer, and the advantage that MapServer has is important. During last editions of the FOSS4G Conference, serious benchmarking of several WMS servers have been done. The description and results of the one done during the FOSS4G 2010 (Barcelona, Spain) are available at:

• Benchmarking 2010 - OSGeo Wiki (detailed description of the benchmarks)
• FOSS 2010 WMS Benchmarking slides (graphs start at page #65)

About MapServer on 64 bit platforms, I have installed it on an old Itanium server under an Ubuntu server operating system. I do not remember it was difficult or tricky, and under heavy load it worked fine.

On the other hand, perhaps the biggest concern MapServer has is, as of version 5 (I don't know about version 6, the current stable one) the lack of WFS-T support.