Look up Skpg in the main arena, he is the one who taught me how to jabo. I can sorta explain it, but im sure he could do alot better.
Get about 10k above your target (its easier the higher you are), select salvo 2 rockets first.
Start your dive at a 45 degree angle diving towards your target, zoom your sight in at the target, pop off rockets, make sure they hit.
You use the rockets as an aiming aide, FIRE, FIRE once you see that your rockets hit the target you know that your bombs will hit when you release.
Like I said, i'm not very good at explaining. I can make a film. That might be easier. Or you can look up skpg in the MA.