Land Rover Repair: 97 Disco electrical or lack there of!, volt meter, 12 volts

Question
Used my good battery to get another car started, reinstalled it in my 97 and now I have no power to anything! No lights, no ignition, nothing at all. Any guidance or direction would be most appreciated! Thanks.

Answer
If the battery worked before you removed it and it does not work now, the first step would be to take a volt meter and check the battery for 12 volts across the terminals.  Perhaps it failed from handling.  If it's okay, you must have a failure in the cables.  They are all visible, so a few minutes with a meter should sort things out