embed KML; Google Earth & Maps, some gadgets, tools, freeware; file import and export; and tutorials

Create Maps with Google Earth & Maps Tutorials:
http://earth.google.com/outreach/tutorials.html#tab2

Very good code playground; you have 3 windows:

• top-left: the manager of the code "pick an API"
• top-right: edit code
• bottom: output

http://code.google.com/apis/ajax/playground/?exp=earth#hello,_earth
http://code.google.com/apis/earth/documentation/examples.html

Other Tools from Google:

• Spreadsheet Mapper 2.0
  Create your own layer of placemarks using Google Docs.
• Embed KML Gadget
  Embed a Google Earth KML file on your website or blog using this gadget.
• Embed Tour Gadget
  Embed a Google Earth KML tour file on your website or blog using this gadget.
• KML Interactive Sampler
  Practice your KML editing using this Google Earth Plug-in tool.

Third-Party Tools:

• shp2kml
  Free tool for creating ESRI shapefiles to KML
• Superoverlay
  Tool for creating regionated image tiles
• Arc2Earth
  Advanced software for importing/exporting GIS data to/from Google Earth
• CamStudio
  Free software for creating screen-capture movies
• GPS Babel
  Free software for converting GPS data to/from Google Earth.
• Google Earth Photo Tag
  Free software for easily using geo-tagged photos in Google Earth.

all tutorials: http://earth.google.com/outreach/tutorials.html#tab1