Your question is quite generic. Do you want to know how you write .geo files yourself? Then have a look at the format documentation (
http://www.horde3d.org/docs/html/_formats.html). If you just want to know how you can convert your models to Horde3D's format, than have a look at the ColladaConv tool (
http://www.horde3d.org/docs/html/_usage ... ml#Content ).
Regarding the editor, what version are you using? SVN? What thing did you miss, that should be updated. I agree that it is not completly up to date, but most of the things should work out of the box if you do a fresh checkout of the complete trunk branch in the community SVN.