Basics about Map Editor
In order to start Map Editing, you will need to access the in game editor that the developers used back on the live servers, To do this you will need complete Admin access.
From there you can access the Editor.
Once in the editor, you can right-click anywhere to see a Menu of all the options available to you.
The top menu is options to save and load maps and many of the options also show you which hotkey it's bound to.
When you place something on the map, press "V" to place it making it apart of the map, However, you cannot move that piece anymore and so you have to press "X" to be able to move it again.
Objects are grouped in a tree structure you can't edit the properties of objects placed directly from the object library, You will need to put them in a group even if it's just one object because you need to edit the properties of the group instead of the object directly, because objects from the library are static.
You can export the objects that you have selected as VRML models. They'll have the same scale and offset as they did in the map editor when you import them into Blender, which is perfect for using as a reference for how big to make something new.
Screenshots for guide purposes to follow.