How do I properly use a Jaguar J gate ?

I have am 02' Jaguar x-type with the j gate for shifting the transmission. I never knew how to use it and am scard to have a problem if I mess around with it. Dose anyone know how it properly works without an issue?|||i drive a 6.0.litre v12 , they all have a j box.firstly if you are sitting for a period say at the lights etc ,just slip it in to n - with your foot still on the brake ,then when your ready slip it back into drive.the manual states when driving on-steep grades use 2nd that's on the left side .so on the left side you should see 2,3,d.this is the manual side and can be selected on the run as required.,there is also a switch at the base of the shifter but this does different things on different models ie,sports mode ,normal mode ,so i hope this helps .