Attached are 3 presets which generate random land correctly scaled for the CS. Also included is a simple tutorial.
Firstly, download and install GeoControl. You can get it here:
http://www.cajomi.de/GeoControl/geocontrol_shop.htm
The author kindly provides a fully-functional 30-day demo but I strongly suggest you do what I did and buy it. It's only about £40 and the full version comes with some stunning pre-sets.
Next, copy this folder (Oblivion) to the presets directory of GeoControl. usually: C:Program FilesGeoControlPresets
Now fire up GeoControl.
Click Terrain Presets (top-right)
Select Oblivion then an island.
Click generate.
Done. A randomly generated island that is scaled to work in the CS.
Click the Project Tab (top-right)
Click Project (top-left)
Select Export terrain then Raw (16-bit) for carrara.
Navigate to your heightfield directory in your Oblivion/Data folder
Name the file 0_0.raw then save.
Open the CS, create a new world space then open the World Editor.
Yous should see your new island.
Click Save then close the World editor.
Save your plug-in.
If you get any height errors (unlikely) select the offending cell in the render window, open the Lanscape editor, select soften vertices then mouse over all the landscape in the render window to take out any height errors.
Done.
For more information on Elder Scrolls, visit
http://elderscrolls.filefront.com 
