As a D3 owner, I haven't looked, but here are two suggestions:
Here's some of the LR4 (V8, yeah!) service manual Land Rover Workshop Manuals > LR4 (LA) V8-5.0L (2010) > Relays and Modules > Relays and Modules - Accessories and Optional Equipment > Communications Control Module > Component Information > Locations > C2778
and Disco4.co.uk is likely to have some helpful info as well.
Good luck with your learning adventure, I had many of the same questions when I first got mine ... very different vehicle to anything I'd ever had before (even other LR's !).
edit: heres a workshop manual from ebay - http://www.ebay.com.au/itm/LAND-ROVE...item2ed01e5897

