You can take a map created with the My Map feature in Google Maps and use the Embed KML gadget at tr.im/embedkml to embed it into your site.
Create maps using the My Maps tab
Create your own custom map in Google Maps using the My Maps feature. Add placemarks, paths and shapes to the map, as well as photos and You Tube videos. You can even embed the map in your website or blog, or view it in Google Earth.
Map spreadsheet data
Enter place data into the Spreadsheet Mapper to dynamically generate KML of your places which you can view in Google Earth!