This KML file shows some sediment core locations in the South Atlantic.

simple kml - file

minimum kml file for placemarks

overlay maps on Googles Earth

defining buildings in a kml file

fix if kml-files from your server do not open in GE

watch and play route in Google Earth

fix if Google Earth does not connect  to server

<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://earth.google.com/kml/2.0">
<Document>
 
  <name>M58/1</name>
 <LookAt>
  <longitude>-18.7587</longitude><latitude>18.505</latitude>
  <range>5000000</range><tilt>0</tilt><heading>0</heading>
 </LookAt>

 <Placemark><name>GeoB8501-2</name><Point><coordinates>-18.7587,18.505</coordinates></Point></Placemark>
 <Placemark><name>GeoB8501-4</name><Point><coordinates>-18.7587,18.505</coordinates></Point></Placemark>
 <Placemark><name>GeoB8502-1</name><Point><coordinates>-18.9338,19.221</coordinates></Point></Placemark>
......
 <Placemark>
  <description>Some<a href="http://www.geochemie.uni-bremen.de/kml/images/8509_RFA.jpg">data</a>   </description>
  <name>GeoB8509-1</name><Point><coordinates>-18.0892,19.451</coordinates></Point>
 </Placemark>
 <Placemark><name>GeoB8509-2</name><Point><coordinates>-18.089,19.451</coordinates></Point></Placemark>
 <Placemark><name>GeoB8516-3</name><Point><coordinates>-17.4012,19.707</coordinates></Point></Placemark>
......

</Document>
</kml>

not essential
kml tag, opens GE
Document tag puts multiple Placemarks in a Folder
name is optional
LookAt Nice to define a view height (range, in m), tilt angle (degrees from vertical view) and heading(degrees from North)

Placemark tag opener with name, Point and coordinates tags in one line for better readability

One Placemark has a description including a hyperlink to a jpeg file. This is avery simple way to display some related information