Any advice on oils- engine/diff/gearbox?

Thanks very nice welcome.

I had an SJ van about 18 years ago, loved it to bits.

Just picked up as my daily drive, a 3 door Vitara 1.6 SE, first registered Feb 04 with 74k on the clock. Really happy with it so far! Obviously has a few niggles but mainly cosmetic, runs really well though!! Any hints-tips-advice would be really appreciated. I plan to change gearbox oil and rear ax...